The invention discloses a hydraulic retractable landing gear mechanism, which comprises a hydraulic pump, a hydraulic oil tank, a first one-way valve, a safety valve, a pressure accumulation regulating valve, a pressure accumulation one-way throttle valve, a pressure accumulator, a pressure relay, a first Second one-way valve, third one-way valve, unloading valve, fourth one-way valve, first two-position two-way solenoid valve, second two-position two-way solenoid valve, fifth one-way valve, emergency discharge two-position two-way Through valve, travel switch, emergency lowering cam disc, main landing gear hydraulic actuator, nose landing gear hydraulic actuator and main landing gear retractable actuator, three sixth one-way valves and three sets of control valve groups. The invention can effectively reduce the power of the hydraulic energy source and has dual emergency lowering modes, is simple to operate and has higher reliability, and ensures that the landing gear of the aircraft can be lowered and landed safely.