The invention provides a self-balancing double-shock wave cam double-stage parallel planar movable gear reducer, which includes an input shaft, a first center wheel, a first inner shock cam, a first movable tooth, a first outer shock cam, a first Roller, second roller, second outer shock cam, second movable tooth, second inner shock cam, second center wheel, third center wheel, etc. Its transmission mechanism adopts double-stage parallel connection, and the calculation method of reduction ratio is more complicated, but it has a wider range of reduction ratio. At the same time, under the same reduction ratio, this configuration has more movable teeth, and the rated The load and impact resistance have been significantly improved; the form of double shock cams is adopted, that is, the movable teeth mesh with the inner and outer shock cams at the same time, thereby realizing the effect of full tooth meshing force transmission; the outer shock cams are opened outside A circle of roller grooves is used to place the roller counterweight, thereby reducing the eccentric mass of the entire mechanism. At the same time, the rollers provide the function of bearings and increase the stability of the transmission mechanism.