Compared with the inside sunshade system, the outside sunshade system increases the skeleton part. It can adjust the light to improve the ecological environment in greenhouse. In the summer when indoor temperature rise to a certain value, it can reflect a part of the sun and diffuse sunshine into the greenhouse according to the different shading rate, achieving the purpose of cooling temperature. Close sunshade screen, at the same time the greenhouse temperature drop 4 ~ 6℃, reduce temperature in the greenhouse. By choosing different shading rate curtain, it can meet the sunshine demand of different crops, in addition, this system also has the hail protection, etc. The outside shading system is controlled by the controller separately.