Telescopic device of belt conveyor

The invention relates to the technical field of coal mine crossheading equipment belt conveyors, in particular to a belt conveyor telescopic device which is characterized by further comprising a sliding groove frame body, a sliding rod, a hydraulic impact idler assembly and an anchoring device. The anchoring device can be anchored in a roadway, and the sliding groove frame body is fixed to the anchoring device. The number of the sliding groove frame bodies is at least two, the adjacent sliding groove frame bodies are connected in a sliding mode through the sliding rods, a cylinder body of the pushing cylinder is hinged to one sliding groove frame body, a piston rod of the pushing cylinder is hinged to the other sliding groove frame body, the hydraulic impact idler assemblies are installed on the sliding groove frame bodies, and one sliding groove frame body is provided with at least one hydraulic impact idler assembly. The belt is laid on the hydraulic impact idler assembly. When the working face carries out