A car networking perceptual system based on OFDM and radar-communication integration comprises a data fusion unit, a driving-information obtaining unit, an echo signal extraction unit, a signal modulation unit, a signal demodulation unit, and a wireless transceiving unit, which are connected with each other. A construction method of the car networking perceptual system based on OFDM and radar-communication integration comprises thirteen steps. By using OFDM to finish the modulation and transmission sharing of self driving information in the invention, on one hand, the car networking perceptual system could demodulate the travelling speed, working condition and movement characteristic data of other vehicles in a cooperative communication mode, on the other hand, a non-cooperative radar detection mode could be used to measure the relative position and motion information between the car and other vehicles around the car so as to provide peripheral target movement conditions for a driver or an automatic drive system in real time to help the driver or the automatic drive system to adopt necessary reasonable measures, thereby improving traffic safety.