Specialization and greening are the development directions of modern agriculture，and it is of great significance to study the impact of specialized production on the agricultural environmental technology efficiency in the context of increasing resource and environmental constraints.On the basis of a theoretical analysis of the relationship between planting specialization and agricultural environmental technology efficiency，based on household survey data of 452 farmers in the main vegetable production areas of Bohai Economic Rim，the super efficiency SBM model，which includes unexpected outputs，is used to measure the agricultural environmental technology efficiency，and the Tobit model is further used to test the effect of planting specialization on the agricultural environmental technology efficiency. The results show that： 1）The average environmental technology efficiency of the sample farmers is 0.521，indicating considerable potential for improvement. 2）From the perspective of facility types，farmers using greenhouses have lower environmental technical efficiency compared to those using tunnels，as the latter employ more advanced green management and techniques.From the perspective of provinces，the environmental technology efficiency of the sample farmers，from lowest to highest，is Tianjin，Beijing，Shandong，Liaoning，and Hebei.3） Planting specialization can significantly improve the agricultural environmental technology efficiency.The conclusion is still valid after the robustness test with the endogenous problem resolved.4） Compared with large-scale farmers and farmers with higher labor capital levels，the effect of specialized farming on improving agricultural environmental technical efficiency is more pronounced for small-scale farmers and those with lower labor capital.Therefore，strengthening policy and green production technical support for specialized planting，and implementing measures tailored to local conditions to encourage specialized production，can be effective ways to promote the green and low-carbon transformation of agricultural production.