The invention discloses a solar power generation device which comprises a mounting rack, a push-and-pull tooth bar, multilayer telescopic solar cell panels, a tooth bar sleeve, a gear, a motor, a motor installing plate and a sector gear. The mounting rack comprises a main support and two rotating shafts, each rotating shaft is provided with one multilayer telescopic solar cell panel, each multilayer telescopic solar cell panel comprises sliding guide rails, a support and a solar power generating panel group, the solar power generating panel group is telescopic in forward, backward, leftward and rightward directions, the push-and-pull tooth bar is mounted in the tooth bar sleeve, the tooth bar sleeve is mounted on an upper cross bar of the main support, a tooth free end of the sector gear is connected with the gravity center position of the rotating shafts, and teeth of the sector gear are engaged with the front segment of the push-and-pull tooth bar. According to the invention, the motor is controlled to drive engaged transmission of the gear and further to adjust the direction of the multilayer telescopic solar cell panels, telescopic adjustment can be carried out on the multilayer telescopic solar cell panels according to requirements, the working area is increased, and solar energy is utilized in a maximized manner.