The invention discloses a passive location method based on multi-channel energy measurement of a wireless sensor network. The method comprises the steps that 1, a sink sends instructions to start a system; 2, sensor nodes successively send data packets after receiving the instructions, and after the final node finishes sending data, all nodes are switched to next channels for repeating the data sending and collecting processes; 3, the sink monitors wireless signal transmission constantly and sends the data to a computer in real time; 4, the computer stores the collected data in an unmanned state as a comparison sample, and the system starts monitoring an appointed region; 5, the computer continuously receives the received signal strength data of the links in different channels and speculates propagation paths possibly influenced by targets according to a signal multi-path propagation formula for the data in a time window; and 6, the computer takes speculation results of multiple links into comprehensive consideration and calculates positions of people.