Closed type jet pipe electro-hydraulic servo valve structure capable of preventing return oil pollution

The invention relates to a closed type jet pipe electro-hydraulic servo valve structure capable of preventing return oil pollution. A U-shaped notch for installing a feedback spring assembly is formed in a valve element, after the valve element is installed in a valve sleeve, clearance sealing is formed between the valve element and the inner hole wall of the valve sleeve, a valve body oil return cavity and a U-shaped notch containing cavity of the valve element are sealed and isolated, and the valve sleeve and a valve body are connected in a clearance sealing mode. A containing cavity where the nozzle and the receiver are located is isolated from an oil return cavity of the valve body. The valve body is provided with an independent flow channel, oil liquid jetted by the nozzle is guided to the oil filter, and the oil liquid is guided into an oil return opening of the valve body through the oil filter. A sealing isolation structure is designed to isolate the feedback spring assembly from an oil return flow fi