Transmission beam and connecting plate positioning device, including a work frame (1), rivet storage box (2), positioning fixture assembly (3), support frame assembly (4) and positioning pin (5), the rivet storage box (2) and the work frame (1) side welding connection, the positioning fixture assembly (3) is fixed on the work frame (1) with bolts, the support frame assembly (4) fixed The locating pin (5) is inserted into the working frame (1) and the locating fixture assembly (3) respectively in the middle position of the locating fixture assembly (3) and the working frame (1). Fix the connecting plate to the work frame (1) using the positioning fixture assembly (3) and the locating pin (5), and then fix the transmission beam to the support frame assembly (4) using the positioning fixture assembly (3) and the locating pin (5). The transmission beam and connecting plate can be riveted quickly, and the assembly accuracy is high.