How to measure trade product quality scientifically and reasonably is a key problem to study the heterogeneity of enterprise product quality. But it still lacks a widely recognized method. And there is no related research to compare and test the results of different methods. From the perspectives of import quality at national level, export quality at firm level and import quality at firm level, this paper puts the main measuring methods into three categories, and measures & tests the Chinese data to find out the most suitable measurement method as for Chinese fact from different perspectives. It arrives at the results as follows: firstly, the application of KHW and SHIBZ into the measurement of import quality at national level and export quality at firm level respectively is more suitable for Chinese fact; secondly, as for the measurement of import quality at firm level, the improvement of current methods by the introduction of transportation costs and exchange rates as instrumental variables of product prices can be used to overcome the problems like sample selection bias; thirdly, the measurement results after the classification of measurement methods of trade product quality at national and firm levels and in import and export aspects can provide a reasonable explanation for changing trends of Chinese import and export product quality in recent years, and the changing trend of general trade import product quality at national level is consistent with the one at firm level. It not only provides measurement reference for future study of Chinese import and export product quality, but also helps us to clarify the reality of import and export product quality and change trend in China.