In a two-degree-of-freedom unilateral collision system with a gap, the two oscillators will produce nonlinear motion. A dynamic model of the two-degree-of-freedom collision system is established, and the two oscillators are analyzed separately by numerical simulation. On this basis, an electronic circuit composed of TL074CN operational amplifier, capacitance and resistance is designed, which is equivalent to the mathematical model. The electronic circuit is simulated by multisim12.0, and the result is consistent with that of numerical simulation. The equivalent electronic circuit model not only has dramatically shortened the calculation time, but also has the advantage of adjustable dynamic parameters, which makes up for the lack of numerical simulation and provides a reference tool for the simulation analysis of multi-degree-of-freedom nonlinear mechanical vibration systems.