The invention discloses an electric drive hydraulic braking method and system for a rail transit vehicle.The method comprises the steps that a hydraulic mechanism is directly driven by a motor to produce pressure oil, a braking unit of the vehicle is driven through the pressure oil, and therefore braking force is produced for wheels of the vehicle.The braking system comprises a control unit, the motor, a mechanical-hydraulic conversion mechanism, a hydraulic foundation braking unit and a sensor.Under the control of the control unit, the motor directly drives the mechanical-hydraulic conversion mechanism to produce pressure oil, and the pressure oil enters the hydraulic foundation braking unit so as to produce braking force for the wheels of the vehicle.The sensor is used for collecting feedback signals of the mechanical-hydraulic conversion mechanism in real time.The feedback signals comprise pressure and/or flow.The feedback signals are transmitted to the control unit.The control unit adjusts the driving force of the motor in real time according to the feedback signals.The electric drive hydraulic braking method and system have the advantages that the structure is greatly simplified, the overall weight is low, and controllability and the braking effect can be improved.