The present invention relates to a method and system for securely setting the system time of a terminal, which fall within the technical field of communications. The method for securely setting the system time of a terminal comprises: a server acquiring an authentication account number; the server determining that the authentication account number has a right to set a system time; the server sending first data to be authenticated to a client tool; the client tool encrypting the first data to be authenticated by using an operator private key to generate first authentication data; the server authenticating the first authentication data; if authentication is passed, a terminal sending second data to be authenticated to the client tool, and the client tool sending the second data to be authenticated to the server; and the server authenticating the second data to be authenticated. In this solution, a system time is set without disassembly and key re-downloading, thereby facilitating the setting of the system time.
