The invention relates to a hydraulic electromagnetic generation device for collecting idle kinetic energy of vehicles, which comprises a protective cover, an energy collector, a one-way valve, a hydraulic motor, an electromagnetic generator, an energy storage device, a pipeline and a buffer device, wherein the buffer device is used for controlling flow rate of fluid in the pipeline, and the energy storage device is an accumulator. The hydraulic electromagnetic generation device is high in energy conversion efficiency, is anti-fatigue, is long in service life and high in reliability, simple in structure, low in production cost, excellent in processing and engineering compatibility, capable of meeting application requirements of vehicle decelerating brake at places such as freeway toll stations, speed bump regions, turning sites and the like, effectively collecting idle kinetic energy generated from the vehicles, has low damage to roadbed and road surfaces, cannot bring any obstacles to running of the vehicles, and can also be used as an emergency power source for power utilization equipment such as lamps on sites such as large-size parking lots, gas station and the like. The energy collector arranged under the road surface can resist corrosion of rainwater and the like so that reliability and stability of power generation floor are improved.