Utilizing a liquid crystal light valve (LCLV), which is produced in China and is made to work in high contrast state, to realize nonlinear joint transform correlation is proposed in this paper. The nonlinear modulation principle of the LCLV has been explained by analyzing the light propagation property in the liquid crystal box. The idea of using high contrast LCLV to realize nonlinear joint transform correlation is confirmed by comparing the computer simulation results with the optical experimental results with the optical experimental results.