1. A method for congestion control in location updating, comprising: setting, by a network side device, location updating congestion control information according to network circumstances, wherein the location updating congestion control information is used by a terminal to obtain a second delay time value by using a preset time parameter algorithm according to the location updating congestion control information; and sending, by the network side device, the location updating congestion control information to the terminal so as to detect, by the terminal, whether a location registration area of the terminal changes; and if a detection result is that the location registration area changes, count time by the terminal and send, by the terminal, a location updating request to the network side device after counted time reaches the second delay time value; wherein the location updating congestion control information comprises congestion degree information; and wherein the process of obtaining a second delay time value by using a preset time parameter algorithm according to the location updating congestion control information comprises: obtaining the second delay time value by using the preset time parameter algorithm according to the congestion degree information in the location updating congestion control information and a preset step size time parameter.