In order to solve the problem of mutual interference when multiple sets of adjacent intelligent radar devices are used at the same time,a radar scheme of direct sequence spread spectrum(DSSS) system is proposed,in which the echoes of the same frequency transmitter are separated by correlation processing. Moreover,the signal processing method of generating range-Doppler map(RDM) from correlation function is proposed. The simulation models of the transmitting and the received signals and the transceiver of the DSSS ultrasonic radar gesture recognition system are established,in which the proposed filter transceiver model simulates the effects of limited-bandwidth,and the gesture echo generation algorithm of transmitted wave backtracking supports the simulation of various complex modulation modes. The simulation experiments show that the DSSS radar adopting the proposed signal processing method is able to separate the signals from different transmitters,and obtain the correct gesture RDMs,with the measurement error within 15% and the resolution of about 4. 03 cm.