The invention discloses a bi-metal composite pipe bending test device. The bi-metal composite pipe bending test device comprises a base, wherein two bending force loading mechanisms, two axial force loading mechanisms and a twisting force loading mechanism are installed on the base, a strain gauge is bonded to the outer wall of a to-be-tested bi-metal composite pipe, a camera is arranged in the to-be-tested bi-metal composite pipe, the to-be-test bi-metal composite pipe is arranged above the base, the twisting force loading mechanism is arranged in the middle part of the to-be-tested bi-metal composite pipe, and two axial force loading mechanisms are symmetrically arranged on two ends of the to-be-tested bi-metal composite pipe, the two bending force loading mechanisms are symmetrically arranged on the left side and the right side of the twisting force loading mechanism, and the bending force loading mechanisms are arranged between the two axial force loading mechanisms. By adopting the bi-metal composite pipe bending test device, the bending force, the axial force and the twisting force can be loaded onto the bi-metal composite pipe, the single-stress bending test can be carried out, the arbitrary combined stress bending test also can be realized, and the situation in the bi-metal composite pipe can be monitored.