In the design of intelligent vehicle collision avoidance system, the intelligent distance measurement is the key technology to avoid the collision of the vehicle and avoid the collision of the vehicle. In the traditional method, the local sensor nodes are used to quantify the tracking method, and the accuracy of the measurement is decreased with the increase of vehicle speed and stop. An intelligent ranging method based on the two time harmonic linear frequency modulated signal detection is proposed. Firstly, the echo detecting and ranging principle is analyzed. And then, the IIR adaptive filter is designed, and the impulse response of the echo signal is realized. The simulation results show that the method has better accuracy and less influence on distance estimation, and can be used in intelligent vehicle collision avoidance system.