The invention discloses a silicon-substrate semiconductor ultrashort pulse laser which comprises a silicon substrate, a buffering layer, a lower light limiting wrapping layer, a lower potential barrier, an active layer, an upper potential barrier, an upper light limiting wrapping layer and an ohmic contact layer. The buffering layer, the lower light limiting wrapping layer, the lower potential barrier, the active layer, the upper potential barrier, the upper light limiting wrapping layer and the ohmic contact layer are sequentially manufactured on the silicon substrate. The lower light limiting wrapping layer, the lower potential barrier, the active layer, the upper potential barrier, the upper light limiting wrapping layer and the ohmic contact layer are of semiconductor laser extension structures. A groove is downwards formed in the surface of the ohmic contact layer. The groove is filled with silicon dioxide materials. A semiconductor amplifier is arranged on one side of the groove. A saturable absorber structure is arranged on the other side of the groove. The silicon-substrate semiconductor ultrashort pulse laser can well solve the problem that GaAs or InP is mainly used as the substrate in existing semiconductor ultrashort pulse lasers and can not be integrated with silicon-substrate micro-electronics.