With an extensive business scope covering all industries of the national economy, the inspection and testing industry is a key field of producer services, and it is the most directly and closely related to quality in the national economic industry against the backdrop of China's economic transformation to high-quality development. Existing studies on the innovation and development of producer services mostly focus on innovation perspectives and innovation models, but the relationship between technological innovation and the competitiveness of producer services has not been systematically explained. In fact, the relationship between technological innovation and the competitiveness of producer services is not only affected by the characteristics of the industry itself but also related to external factors such as the government. Technological innovation is an important factor that affects the degree of specialization of the producer service industry.#br#Therefore, this study takes the inspection and testing industry as an example to study the relationship between technological innovation and producer service industry competitiveness and the effect of government support on the relationship between the two. It first collects and organizes the data of listed companies in the inspection and testing industry, and finally screens the unbalanced panel data of listed companies from 2015 to 2020. Then it constructs an evaluation index system for the competitiveness of inspection and testing enterprises based on the Porter Diamond model in three dimensions: basic competitiveness, development competitiveness and performance competitiveness.Finally, it measures and evaluates the competitiveness of inspection and inspection enterprises using the factor analysis method. In a whole, the study makes an empirical analysis of the relationship between technological innovation and the competitiveness of inspection and testing enterprises and studies the moderating effect of government support on the relationship between technological innovation and the competitiveness of inspection and testing enterprises.#br#The research results show that technological innovation promotes the development of the inspection and testing industry. The stronger the technological innovation ability is, the higher the competitiveness of inspection and testing enterprises will be. The age of enterprises has no obvious effect on the competitiveness of inspection and testing enterprises, and there is a negative correlation trend. Cash flow has a significant positive impact on the competitiveness of inspection and testing enterprises, while capital density has a negative correlation with the competitiveness of inspection and testing enterprises. The research results on the moderating effect of government support on the relationship between technological innovation and the competitiveness of inspection and testing enterprises show that, firstly,fiscal subsidies have a moderating effect on the relationship between technological innovation and the competitiveness of inspection and testing enterprises. The higher the degree of government subsidies, the stronger the positive impact of technological innovation on the competitiveness of inspection and testing enterprises. Financial subsidies not only increase technological innovation investment for free and promote the conversion of technological advantages to product advantages, but also attract venture capital to support enterprise technological innovation activities through the information transmission effect. Government financial subsidies for enterprises can reduce investors' risk assessment of enterprises and improve investment confidence. Meanwhile, government financial subsidies can reduce industry entry barriers and increase the possibility for enterprises to transform their innovation advantages into productivity. Secondly, the moderating effect of high-tech enterprise policy on the relationship between technological innovation and the competitiveness of inspection and testing enterprises is not significant. The possible reasons are that the policy support of high-tech enterprises fails to effectively guide the simultaneous growth of technology and market demand of inspection and testing enterprises, the overcapacity of homogeneous products fails to form an effective stimulus to technological innovation, and the industrial profit advantage fails to be improved. Therefore, factors such as the specificity of industrial policies, incentive methods and regulatory measures need to be fully considered.#br#On the basis of the above research conclusions, policy recommendations are put forward from five aspects to enhance the industrial competitiveness of China's producer service industry: forming a modern enterprise technology innovation management mechanism, increasing technological innovation capital investment, cultivating technological innovation talents, fulfilling the guiding role of government policies, and establishing a systematic and sound industrial development supervision system.#br#