Disclosed is a skin dilator, comprising an expander (11), a pipe network provided on the skin-side surface wall (111) of the expander (11) composed of longitudinal tube (22) and horizontal tube (21) having a reticular structure and communicating with each other, and a guide tube (24) communicating with the pipe network. The skin dilator further comprises several burrs (25) distributed on the skin-side surface wall (111) of the expander (11), and several small apertures (23) communicating the inner cavity of the tube with the outside are provided on both of the longitudinal tube (22) and horizontal tube(21). The tissue expander can be infused biological agents by the filling port to the skin expanding site through the small apertures (23), which may accelerate the expansion growth of skin, prevent skin complications, such as necrosis.