Based on the panel data of 30 provinces from 2008 to 2017, Super-SBM model was constructed to measure the green technology innovation efficiency of regions. Then, the threshold panel model was used to empirically study the non-linear impact of trade on the spillover efficiency of green technology innovation in China by taking environmental regulation and industrial agglomeration as threshold variables. The results show that the efficiency of China"s green technology innovation grows rapidly, but the regional development is "unbalanced". The eastern region is far ahead of the central and western regions. According to the threshold results, the spillover of trade on regional green technology innovation efficiency has a significant "double threshold" effect of environmental regulation and industrial agglomeration. From the perspective of action mechanism, trade and green technology innovation efficiency under environmental regulation have U-shaped relationship. As the intensity of environmental regulation increases, the spillover "crowding out effect" gradually turns to "incentive effect", and the influence changes from negative to positive and the effect gradually increases. Under industrial agglomeration, trade and green technology innovation efficiency have N-shaped relationship. Only when the level of industrial agglomeration crosses the second threshold, the influence is significantly positive. The effect of environmental regulation on the efficiency of green technology innovation is obvious as direct promotion and indirect threshold, while the effect of industrial agglomeration on the efficiency of green technology innovation is only indirect threshold.