The invention discloses a fuel gas and EGR coupled direct injection system. A low-pressure EGR pipe is connected with an exhaust pipe and a high-pressure EGR pipe, a low-pressure EGR valve is installed on the low-pressure EGR pipe, and a high-pressure EGR valve is installed on the high-pressure EGR pipe; an inlet of an EGR pump is connected with an exhaust manifold through the high-pressure EGR pipe, an outlet of the EGR pump is connected with an inlet of an EGR air track, an outlet of the EGR air track is connected with an EGR end inlet of a high-pressure mixer through an air outlet pipe of the EGR air track, and an EGR air track control valve is arranged on the air outlet pipe of the EGR air track; an outlet of a liquidation fuel gas vessel is connected with an inlet of a fuel gas pump, an outlet of the fuel gas pump is connected with an inlet of a fuel gas track, an outlet of the fuel gas track is connected with a fuel gas end inlet of the high-pressure mixer through an air outlet pipe of the fuel gas track, a fuel gas track control valve is arranged on the air outlet pipe of the fuel gas track, an outlet of the high-pressure mixer is connected with a nozzle through a nozzle connecting pipe, and the nozzle is installed on a cylinder or in an air inlet channel close to the cylinder.