Abstract: The remote monitoring and control systems of semi-autonomous robots applied to hazardous environments are introduced.Video image transmission and remote control are realized via the combination of wireless local area network(WLAN) and CDMA mobile communication network.The acquisition,format conversion and compression of video data by DM642,and the design of the robot motion control structure,robot control protocol and wireless transmission protocol are described in detail.Finally,experiments on wireless image transmission and wireless control are analyzed and discussed.