The embodiment of the invention discloses a security authentication method, related equipment and a communication system based on transport layer security (TLS). The security authentication method based on a TLS protocol includes the steps that a client sends client initialization handshake information to a server, the client initialization handshake information carries N algorithm set identifications, and an algorithm set corresponding to each one of M algorithm set identifications of the N algorithm set identifications comprises an SM2 algorithm; server initialization handshake information sent by the server is received, and the server initialization handshake information carries a first algorithm set identification which is one of the M algorithm set identifications; security authentication is carried out on the basis of a first algorithm set corresponding to the first algorithm set identification and the server. A mechanism for data transmission through the SM2 algorithm is provided, so that advantages of the SM2 algorithm in the security factor are brought into full play, and safety and performance of security authentication and data transmission are improved.