Hydraulic type automatic air bleed valve of fuel oil system

The invention provides a hydraulic automatic bleed valve for a fuel system, which comprises a shell, a piston, a leather cup arranged on the periphery of one end part of the piston, a step part arranged on the periphery of the other end part, close to a bleed end cover, of the piston, a spring component sleeved on the periphery of the step part, and an adjusting nail arranged in the piston, the packing cup and the adjusting nail axially move in an inner hole of the shell along with the piston, a blocking block is arranged on the inner circumference of the end of the deflation end cover, a gap exists between the blocking block and the deflation end cover, a gear pump rear high-pressure oil way is arranged on the shell, and a deflation port and an oil tank booster pump rear oil way port are sequentially arranged on the periphery of the deflation end cover from left to right. According to the hydraulic type automatic air bleed valve of the fuel system, the problem that a traditional air bleed valve is poor in co