The invention relates to a combined underground rescue robot based on wireless CSI and a rescue method. The combined underground rescue robot comprises a robot A, a robot B and a WiFi-based wireless detection module, wherein the WiFi-based wireless detection module comprises a wireless router installed on the robot A, a receiving antenna installed on the robot B, a band-pass filter and a microprocessor with an intel 5300 wireless network card. During working, firstly, the WiFi-based wireless detection module quickly judges whether any people are in a detection range, if not, the combined underground rescue robot immediately moves to a next detection range, if so, the combined underground rescue robot uses an orientation judgment algorithm to pre-judge the area where people are, a camera isturned on to scan the pre-judged position where the people are and confirm the position of the people, and the position of the robot is uploaded to a ground command center. The combined underground rescue robot is not affected by the environment with low visibility or many obstacles during detection, the detection range is large, the speed is high, positioning is accurate, the search and detection efficiency are high, the power consumption is low, and the operation time is long.