Using micro enterprise survey data of China provided by the World Bank, based on the perspective of enterprise heterogeneity, this paper studies the relationship between legal service and China’s manufacturing enterprises exporting behavior. The results show that the effect of legal services on the export presents “inverted U + U”, namely the increase of legal service quantity has positive enterprises’ export at first, and after reaching the first threshold, the effect becomes negative, but after reaching the second threshold, it turns positive again. The effect also has regional difference with significant impact on the eastern region but non-significant impact on the middle and western regions. At present, the quality of legal service decides the orientation of the effect on enterprises’ export. The increase of low-quality legal service cannot promote enterprises’ export, while only high-quality legal service can play the role. Therefore, in order to advance the transformation and upgrading of quality legal service by advancing the transformation and upgrading of legal services, the education for layer should promoted, and the forms of legal services should be innovated from the perspective of “Internet+law”.