Security establishment method and related device

The invention provides a security establishment method and a related device, which are used for selecting an adaptive security establishment scheme for a communication device and ensuring communication security. In the method, a first communication device initiating proximity service communication determines a target scheme from a plurality of schemes, for example, the target scheme is determined based on a scheme selection rule, and sends a request message to request a receiver to use the target scheme to perform security establishment with the first communication device; the second communication device receiving the request message sends a first message to the first communication device based on the online state to indicate whether to agree to use the target scheme for secure establishment therewith. The second communication device may agree to use a network-side-independent or network-side-dependent secure setup scheme when within network coverage; and when the user is not in the network coverage range, the user agrees to use a security establishment scheme which does not depend on the network side. Through negotiation of the first communication device and the second communication device, the first communication device and the second communication device can establish a secure connection using a co-supported secure establishment scheme.