A discovery method and apparatus based on a service-based architecture, where the method includes a control network element sending a discovery response to a first functional network element, where the discovery response includes a determined security parameter and an access address or an identifier of a second functional network element. The first functional network element receives the discovery response from the control network element, and sends an access request to the second functional network element based on the address or the identifier of the second functional network element, where the access request includes the received security parameter. The second functional network element receives the access request from the first functional network element, verifies correctness of the security parameter, and determines, based on the correctness of the security parameter, whether the access request is authorized by the first functional network element.