Cheap labor force has always been a comparative advantage of China’s processing trade. However inrecent years, rising labor costs forced China to accelerate the transformation ofprocessing trade. The previousresearch mainly focuses on analyzing the scale of processing trade growth, the relationship between labor costand the export of processing trade, few have done on explaining the relationship between the two from the dualmargin perspective of the processing trade growth. In this paper, by using the micro trade data of HS code (6 digits,2002~2013) and the decomposition method of Amurgo-Pacheco and Pierola (2008), the authors calculate the dualmargin of the export growth of China’s processing trade to 17 major trading partner countries; the dual margin ofthe China’s processing trade export growth effected by labor cost, import and export market scale, trade cost, laborproductivity, multilateral resistance, external shocks and other factors were calculated through the Tobit model.Also, the PPML method is used to test the robustness of the model. Subsequently, an empirical test of dual margin isdone by different levels of technology products. The study finds that labor cost mainly affects the intensive marginof the export growth of China’s processing trade, while the influence is very small to the extensive margin, and theimpact of other factors is not the same; dual margin of high tech export products affected by labor cost is lower thanthose of middle and low technology products.