The invention relates to a robot telescopic arm, and belongs to the technical field of robots. The invention solves the problems of high risk and high labor intensity of furnace discharge operation. Comprising a support assembly, a telescopic driving part, a guide rail, a telescopic transmission assembly, a moving trolley and a grabbing executing mechanism, the guide rail is arranged on the upper portion of the support assembly, the support assembly is connected with the moving trolley through the guide rail, the telescopic driving part is arranged at the rear end of the support assembly, and the support assembly is connected with the telescopic transmission assembly; the telescopic driving component is connected with the telescopic transmission assembly, the telescopic transmission assembly and the moving trolley are installed, and a grabbing executing mechanism is arranged on the moving trolley. The device can complete various complex operations, improve the working environment, guarantee the personal and property safety, improve the working efficiency and reduce the labor intensity and difficulty.