A variable damping shock absorber includes a housing and a piston rod capable of sliding along an inner wall of the housing. A first damping unit is fixedly arranged on the piston rod, which moves with the piston rod and generates frictional force with the inner wall of the housing. An accommodating space is formed between a part of the piston rod and the inner wall of the housing. A second damping unit matched with the inner wall of the housing is arranged in the accommodating space. The second damping unit vertically moves along the inner wall of the housing, and generates frictional force with the inner wall of the housing.
