Abstract The problem of bifurcation and chaos of a four-side fixed thermo-electromagnetic-mechanic coupling rectangular thin plate is studied. Considering the effect of temperature, the vibration equations of the rectangular thin plate under the action of mechanic field, the temperature and steady transverse magnetic field are derived. By Melnikov function method, the chaos condition and judging criterion of the system under the condition of Smale horseshoe map are given. The vibration equations are simulated numerically. By some examples, the bifurcation diagram, the Lyapunov exponents diagram, the displacement wave diagram, the phase diagram and the Poincare section diagram of the system are obtained. The influences of electromagnetic field and the temperature on system vibration properties are analyzed. From the simulation, we can control the characteristics of the vibration system and can make the system become chaos motion or avoid chaos motion by changing the temperature and electromagnetic parameters.