The invention discloses a micro piezoelectric-electromagnetic composite power generation device, which comprises an electromagnetic power generation unit, a piezoelectric power generation unit, a planetary gear acceleration mechanism, a housing and a bulge structure, wherein a brushed DC motor structure is adopted by the electromagnetic power generation unit; a cantilever beam-type piezoelectric vibrator structure is adopted by the piezoelectric power generation unit; and the electromagnetic power generation unit and the piezoelectric power generation unit convert external mechanical energy into electric energy. Rotating speed multiplication of a sun gear is achieved by reasonably matching various gear teeth of the planetary gear acceleration mechanism, so that the speed of cutting a magnetic induction line by a coil and the frequency of exciting a piezoelectric vibrator by the bulge structure are improved; and the power generation efficiency is further improved. Two different power generation mechanisms are achieved by the same mechanism, so that the effect of superposing and amplifying output electric energy is achieved; and the power generation efficiency is further improved through ingenious combination with the planetary gear acceleration mechanism.