The invention discloses a steam compressor unit directly driven by wave energy. The steam compressor unit comprises an oscillation floater, a floater arm, a mechanical transmission device, a mechanical energy storage device, an energy storage control assembly, a coupling and a compressor. The oscillation floater is connected with the floater arm. The collected wave energy is transmitted into the mechanical energy storage device through the mechanical transmission device, and the compressor is driven by controlling the mechanical energy storage device through the energy storage control assembly. According to the steam compressor unit directly driven by the wave energy, the wave energy is collected by the oscillating floater and directly drives the steam compressor to run, losses in the energy conversion middle process can be effectively reduced, and the utilization efficiency of the wave energy is improved; and the energy storage and discharge process of the mechanical energy storage device is controlled through the energy storage control assembly, the problems of fluctuation and instability of the wave energy can be solved, and the system running reliability can be improved.