Pre-pressurizing jet pump

The invention provides a pre-pressurizing jet pump which comprises a fuel inlet connector, a pump shell, a nozzle, a support bracket and a pump outlet shell, wherein the area ratio of the jet pump is 50-80; the support bracket is of an integrated structure composed of an inner ring, an outer ring and a connecting rib; the inner ring and the outer ring are concentric circles; the pump shell is a cylinder structure; an inner chamber body and an outer chamber body are machined inside the cylinder body; the inner chamber is an L-shaped channel; a horizontal section of the L-shaped channel is a cylinder cavity with a variable diameter; the outer chamber is an annular structure; a positioning groove is machined at the rear end of the outer chamber; a fuel inlet connector is welded with the outer surface of the front end of the pump shell; an oil inlet channel of the fuel inlet connector is communicated with an upright section of the inner chamber; the nozzle is arranged at the rear part of the horizontal section of