The invention aims to solve the problem that rainwater on the plant leaves is difficult to reasonably utilize at present, and discloses a device for reasonably utilizing rainwater on plant leaves. Thedevice comprises control assemblies, a guide plate, guide grooves, sliding rods, first coil springs, sleeves, plugboards, scraping blocks, rollers, first motors, racks, support racks, lantern rings,first rotating shafts, rotating frames, second coil springs, second motors, support frames, rotating barrels, pull cords, second rotating shafts, sliding blocks, fastening screws, pull cords, first contact pieces, second contact pieces, third coil springs, positioning blocks, guide blocks, third contact pieces, fourth contact pieces, third motors and stop blocks. The device can control the plant leaves conveniently, so that the rainwater on the plant leaves flows to roots of plants, the plants can sufficiently absorb the rainwater, and growth of the plants is better promoted.