Agricultural equipment in the field operation process continues to produce mechanical vibration, capture its vibration energy and realize agricultural machinery self-power supply is of practical significance. For the application of vibration energy harvesting device can’t match the external excitation or mechanical structure vibration frequency, energy harvesting efficiency is low, a resonance frequency adjustable piezoelectric-electromagnetic coupling vibration energy harvesting device was designed, combining the use of bicrystalline piezoelectric cantilever beam structure, and the combination of electromagnetic induction and piezoelectric effect, to achieve the resonance frequency adjustable from 14.8Hz to 31.0Hz, and to broaden the bandwidth of the vibration energy harvesting. Based on Hamilton’s principle, an electromechanical coupling mathematical model was established, which revealed the regulation mechanism of the resonant frequency of the system. Through indoor experiments, the effects of different load resistances, excitation acceleration, excitation frequency, and magnetic distance on the power generation performance were investigated, and the optimal load resistance configurations and resonant frequencies under different magnetic distances were determined. Field tests were carried out by using EH2604 high power tractor to study the power generation performance of the vibration energy recovery device under the soil surface of farmland. The results showed that when the optimal load resistances for the cantilever piezoelectric patch, electromagnetic coil, and bending piezoelectric transducer were 850kΩ, 990Ω, and 300kΩ, respectively, and the optimal magnetic distance was 53mm, the vibration energy output power peaked. The device can effectively collect vibration energy under different magnetic distances and vehicle speeds, and the output power tended to increase with the increase of vehicle speed, and the magnetic distance was 38mm, and the maximum output power was 25.97μW at a vehicle speed of 12km/h. The research result can provide technical solutions and ideas for the development of self-supply energy system of agricultural machinery for reference.