Export product quality is an important indicator to measure the upgrading of manufacturing industry.How producer services trade liberalization affect export product quality is the focus of this paper.Firstly,the empirical analysis finds that producer services trade liberalization can improve enterprises' export product quality,which is still established after the robustness check.The heterogeneity analysis shows that producer trade liberalization of other business service sectors and financial service sectors has a more significant effect on enterprises' export product quality,and producer services trade liberalization has a more significant effect on the export product quality of private enterprises and the eastern region.Secondly,this paper finds that producer services trade liberalization can improve export product quality through two mechanisms of productivity of enterprises and manufacturing servitization,and the influence is nonlinear,showing an inverted " U " shape.The conlusion is that the producer services trade liberalization can improve export product quality.The manufacturing industry should still focus on the development of manufacturing entities and service-input is supplemented.