The invention relates to a method for manufacturing a thin film transistor substrate, which comprises the following steps: providing a substrate, manufacturing a polysilicon film pattern on the substrate, wherein the polysilicon film pattern comprises source electrode contact areas and drain electrode contact areas of a plurality of first type thin film transistors, and the source electrode contact areas and the drain electrode contact areas of a plurality of second type thin film transistors; performing heavy doping on the source electrode contact areas and the drain electrode contact areas of the first type thin film transistors; forming a grid electrode insulating film on the surface of a polysilicon film, and forming grid electrode metal wires on the grid electrode insulating film; performing self-alignment type heavy doping on the source electrode contact areas and the drain electrode contact areas of the second type thin film transistors; forming dielectric layers on the surfaces of the grid electrode insulating film and the grid electrode metal wires; manufacturing a connecting passage to communicating the polysilicon film to the surfaces of the dielectric layers; and forming electrode metal wires in the connecting passage, wherein the heavy doping of the first type thin film transistors and the heavy doping of the second type thin film transistors compensate each other. The manufacturing method reduces the amount of masks, and has superiority in the manufacturing cost.