A four-wheel independent suspension system for an electric wheelchair includes a chassis, two front wheels each fixed to a front rod respectively, and two rear wheels each fixed to a rear rod respectively. The chassis includes a rail extending in a width direction of the chassis, each of the front and rear rods has one end connected to a square first connecting sleeve, in the first connecting sleeve is disposed a first shock absorber which includes a rectangular outer pipe, and a rectangular inner pipe disposed in and rotated degrees with respect to the outer pipe, the edges of the inner pipe are abutted against the inner surface of the outer pipe, between each of the edges of the inner pipe and the inner space of the outer pipe is disposed an elastic rubber, the inner pipe of each of the first shock absorbers is sleeved on the rail.
