In this paper,a new behavioral model of high optical feedback（moderate and strong optical feedback）based on orcad 10.5 of cadence is proposed to represent the optical feedback self-mixing phenomenon and to simplify the solution of nonlinear equations involved in this problem.At the same time,it not only establish an behavior model of the optical feedback sensor and build a platform to combine hardware and software,but also develop new methods for signal processing of target measurements such as displacement,velocity and distance.