Aero-engine fuel system and jet pump with variable nozzle-to-throat clearance of system

The invention discloses an aero-engine fuel system and a jet pump with variable nozzle-to-throat clearance of the system to guarantee the matching performance of a jet pump structure and the fuel system thereof. The jet pump with variable nozzle-to-throat clearance comprises an elastic part arranged in a pump body, a throat tube is an independent entity and is movably arranged in the pump body, the pump body is provided with a first stop point and a second stop point of the throat tube, and the elastic part provides elastic force for the throat tube, so that the throat tube is kept in the first stop point in the pump body; when the jet pressure of the throat tube is larger than a set value, the elastic force of the elastic part can be overcome, and the throat tube is forced to move towardsthe second stop point; the distance between the throat tube and a nozzle is defined as the nozzle-to-throat clearance, and the nozzle-to-throat clearance is largest when the throat tube is located atthe first stop point and