A robot wrist structure includes: a case, a first motor, a second motor, a first transmission mechanism, a second transmission mechanism, a first driving bevel gear, a second driving bevel gear, a driven bevel gear, a retaining fame, and an output connecting member; wherein the first motor and the second motor are mounted on the case, the first driving bevel gear, the second driving bevel gear and the driven bevel gear are respectively rotatably mounted in the retaining frame, the first driving bevel gear and the second driving bevel gear are both in mesh with the driven bevel gear, the first motor is connected to the first driving bevel gear by the first transmission mechanism, the second motor is connected to the second driving bevel gear by the second transmission mechanism, and the output connecting member is fixedly connected to the driven bevel gear.