A Magneticcoupled Sliding Vehicleroad Energy Harvesting device (MSVEH) is proposed to harvest the mechanical energy generated by moving vehicles. The energy harvesting device is flush with the road surface, which can effectively reduce impact on vehicle while harvesting energy. The magnetic coupling drive mode can realize the noncontact motion transmission, so as to convert the dynamic seal into a static seal, and the idea of full seal design can helps to improve the reliability of the device. The sliding part generates horizontal motion under the bidirectional excitation of the vehicle, and the motion is transmitted to the generating unit through the magnetic force to cause the relative motion of the magnet plate and the coil to generate electricity. The joint design of oneway bearing and reversing gear realizes the adaptive device in complex traffic environment, adapt to the bidirectional excitation of the wheel and outputs oneway rotation. The mathematical formula of magnetic force between permanent magnets is established and calculated and obtained the magnetic force curve. The dynamic model of the system was established to study the electrical characteristics of the system. The influence of the sliding displacement and excitation frequency parameters under external load on the electrical output was explored. The results show that the sliding displacement has significant influence on the output performance of the device. When the load resistance is 60 Ω, the displacement is 20 mm and the frequency is 5.0 Hz, the peak voltage and peak power are 10.2 V and 1.734 W, respectively.