Embodiments of the invention relate to the technical field of Internet and disclose an identity authentication method, and related equipment and system. The method comprises the following steps that service equipment receives authentication information which is sent by user equipment, wherein the authentication information comprises an input character string and a time input characteristic of the input character string; the service equipment authenticates whether the input character string is the same as a registration character string corresponding to an account bound to the user equipment, and if same, the service equipment authenticates whether the time input characteristic is matched with a time input characteristic model corresponding to the registration character string; and if the time input characteristic is matched with the time input characteristic model corresponding to the registration character string, the service equipment sends an identity authentication success message to the user equipment. By applying the embodiments of the invention, the security for identity authentication can be effectively improved, and the hardware requirement of the equipment is reduced.