1. A network access method, comprising: determining with a mobile communications terminal if a network identity of a visited public land mobile network (VPLMN) exists in an equivalent public land mobile network (EPLMN) list, wherein the EPLMN list comprises a network identity of a home public land mobile network (HPLMN) and the network identity of the VPLMN owned by a visited location operator who signs a roaming agreement with a home location operator who owns a subscriber identity module (SIM) card used in the mobile communications terminal; obtaining a shared network information stored in an operator's server and searching for the network identity of the VPLMN from the shared network information upon a condition that the network identity of the VPLMN does not exist in the EPLMN list, wherein the operator's server is the home location operator's server or the visited location operator's server in which the visited location operator signs a roaming agreement with the home location operator; adding the network identity of the VPLMN to the EPLMN list; and accessing a network based on the EPLMN list.