The invention discloses a multi-point wall temperature measuring device for a rod bundle fuel assembly under a motion condition. The multi-point wall temperature measuring device comprises one or moreisolating ceramic pipes, and annular grooves are formed in the inner circumferential walls of the isolating ceramic pipes in the circumferential direction of the isolating ceramic pipes. Temperaturemeasuring rings are arranged in the annular grooves, and one or more sheathed thermocouples are arranged on the inner walls of the temperature measuring rings. When heat-transfer characteristic experimental study is carried out on the simulating rod bundle fuel assembly, metal round pipes are utilized to be powered on and heated to serve as heating element pipes. The annular grooves are formed inthe inner circumferential walls of the isolating ceramic pipes, the temperature measuring rings are arranged in the annular grooves, and the one or more sheathed thermocouples used for temperature measuring are arranged on the inner circumferential walls of the temperature measuring rings. During using, according to the axial length of the heating element pipes, temperature measuring point positions are determined; and then the isolating ceramic pipes are fixed to the temperature measuring point positions, and the temperature measuring rings transmit heat on the temperature measuring point positions to the sheathed thermocouples to achieve accurate measuring of the local wall surface temperature of the heating element pipes.