The invention provides a flow control method and device and vehicle-mounted equipment. When an air compressor works in a preset surge region, the rotation speed of the air compressor and the opening degree of an air outlet throttle valve are adjusted according to a correction value of the total air inlet flow and the pressure value of the air compressor, so that the air compressor exits the presetsurge region; and meanwhile, when the air compressor works in a preset surge region, the correction value of the total air inlet flow of the air compressor is greater than the total air inlet flow, and the increased bypass air can be discharged by adjusting an air side bypass solenoid valve, so that the air input into a fuel cell does not change, and it is guaranteed that the power provided by the fuel cell can reach the preset output power specified by a vehicle controller.