The present disclosure provides a power unit for a bionic robot, a robot joint and a robot. The power unit comprises: a shell, wherein a stator is embedded in the shell, a rotor is embedded in the stator, a rotor shaft is embedded in the rotor, bearings are disposed between the rotor shaft and the shell, a driving shaft is embedded in a central portion of the rotor shaft, a first driving wheel is disposed on the driving shaft, two transmission shafts are disposed in the rotor shaft, a first driven wheel and second driving wheels are disposed on each of the transmission shafts, the first driven wheel is engaged with the first driving wheel, a sun gear shaft is disposed in the rotor shaft, the sun gear shaft and the driving shaft are coaxially disposed, and a synchronizer and second driven wheels are disposed on the sun gear shaft.