With the steady progress of the _"Belt and Road_" initiative the green development of countries along the route has become one of the priorities of the initiative. This paper adopts the global super-efficiency SBM model to measure the green development performance of 35 countries along the _"Belt and Road_" and analyze the spatial-temporal evolution as well as the spatial correlation. On this basis the paper uses the Spatial Durbin Model to explore the spatial correlation and driving factors of green development efficiency of the _" Belt and Road_" countries. The results show the following findings. The overall trend of green development efficiency of the countries along the route is a _" W_" shape and the regional differences of _"Western Asia and North Africa area>South Asia area>Central and Eastern Europe area>Southeast Asia area> Central Asia area_" are obvious. From the perspective of direct effects economic development and openness have a significant role in promoting the efficiency of green development in countries along the route and urbanization and infrastructure construction have significant inhibitory effects. From the perspective of spatial spillover effects economic development and infrastructure construction have positive spillover effects. Urbanization industrial structure and openness have negative spillover effects. Therefore we should fully consider the spatial relevance of the green development of countries along the _"Belt and Road _"strengthen cooperation in new energy and technology between countries optimize the industrial structure attach importance to the role of human capital introduce green investment and promote the green _"Belt and Road_".