The invention relates to a method for remotely maintaining multiple terminals based on a 3G network, comprising the following steps of: setting up a proxy server used for intercepting port connection and NAT (Network Address Translation) port mapping of a controlled terminal; carrying out NAT port synchronous mapping on connecting ports of a plurality of controlled terminals by the proxy server subjected to 3G network encryption connection of the plurality of controlled terminals and the proxy server, and transforming the controlled terminals into remote maintenance ports; and carrying out data exchange on remote maintenance terminal software with the controlled terminal through the maintenance ports, thereby realizing maintenance work on each controlled terminal work station. The invention provides a multiterminal remote maintenance method which has the advantages of high speed, safety and low cost and overcomes the disadvantages of high maintenance cost and large human resource consumption of the traditional method.