The invention relates to a vehicle vibration power generating device. The vehicle vibration power generating device adopts a cantilever beam and a ratchet wheel as a vibration picking mechanism, adopts a one-way bearing and a gear set as a vibration mechanical energy transmission mechanism and adopts a direct current permanent magnet generator as an electromechanical energy conversion mechanism, and an electric energy processing circuit with a USB interface processes irregular alternating electricity to supply electricity to vehicle-mounted electronic equipment. According to the vehicle vibration power generating device, the cantilever beam and ratchet wheel mechanism is used for pricking vibration, linear movement in the vertical direction in the running process of a vehicle is converted into rotary movement, an efficient one-way gear mechanism drives the low-damping permanent magnet direct current generator to work, and the transmission and conversion efficiency of vibration mechanical energy can be obviously improved compared with a common linear vibration power generating device. The vehicle vibration power generating device generates electricity with renewable energy sources, is high in vibration picking efficiency and energy transmission and conversion efficiency, is long in service life, adopts the USB interface, is suitable for most vehicle-mounted electronic equipment, and is high in universality.