The invention discloses a sun-shading system applied to a permafrost roadbed side slope, and belongs to the field of sun-shading system design. According to the sun-shading system applied to a permafrost roadbed side slope, a sun-shading rack is arranged on the permafrost roadbed side slope; a temperature controlled switch is arranged on a crushed rock protection slope; a sun-shading net box is arranged in the sun-shading rack; a sun-shading net is stored in the sun-shading net box; a motor and a transmission gear group are arranged; rotary gears are arranged on the periphery of the sun-shading rack, and are connected with the transmission gear group through hinges; the net edges of the sun-shading net are connected with the hinges. The environment temperature is sensed through the temperature controlled switch to control forward rotating or reverse rotating of the motor to intelligently control spreading and shrinking of the sun-shading net, so that the problem in the prior art that the thermal switch effect of the crushed rock protection slope is adversely influenced due to an obvious increase of the exposed crushed rock temperature when the crushed rock protection slope is adopted can be solved, the hot melt phenomenon of the permafrost roadbed side slope can be effectively prevented, and the smooth progress of a project can be guaranteed.