The invention provides a power generation device for energy saving illumination, and aims to solve the problem that water flowing out from a traditional tap cannot generate electricity. The power generation device comprises a rotating wheel, a water pipe, a permanent magnet, a coil and an accumulator 1; the coil is arranged around the rotating wheel; the permanent magnet is strip-shaped or horseshoe-shaped, and is fixed on the rotating wheel; blades are uniformly distributed on the outer circle of the rotating wheel; water sprayed by the water pipe dashes to the blades so as to drive the rotating wheel to rotate; the coil cuts a magnetic induction line to generate electric energy; the the electric energy is stored in the accumulator 1. The water drained by the water pipe is used for driving the rotating wheel to rotate, and the rotating wheel drives the permanent magnet to rotate, so that the energy is saved. An illumination system comprises a circuit system connected with the accumulator; and the circuit system is provided with an illumination lamp and an adjusting switch for adjusting the brightness of the illumination lamp. The electric quantity in the accumulator is insufficient at times, the brightness adjusting switch can be used for reducing the power consumption, so that the illumination time is prolonged.