A method for implementing a cross-domain jump, comprising the following steps: a second domain name server obtaining a cross-domain jump request of jumping from a first domain name to a second domain name sent by a browser, the cross-domain jump request comprising a cross-domain user identifier corresponding to a first identifier of a user in the first domain name; the second domain name server obtaining a second identifier of the user in the second domain name corresponding to the cross-domain user identifier, and generating a user login state of the user in the second domain name according to the second identifier, characterized in that wherein before the step of a second domain name server obtaining a cross-domain jump request of jumping from a first domain name to a second domain name sent by a browser, the method further comprises: the browser obtaining a request of jumping from the first domain name to the second domain name, and generating the cross-domain user identifier according to the second domain name and the first identifier; the browser generating the cross-domain jump request according to the cross-domain user identifier and the second domain name and sending the cross-domain jump request to the second domain name server, wherein the step of the browser generating the cross-domain user identifier according to the second domain name and the first identifier comprises: the browser finding a registered identifier and a second domain name key corresponding to the second domain name, and combining the registered identifier and the first identifier; the browser encrypting the combined identifier according to the second domain name key to generate the cross-domain user identifier. a second domain name server obtaining a cross-domain jump request of jumping from a first domain name to a second domain name sent by a browser, the cross-domain jump request comprising a cross-domain user identifier corresponding to a first identifier of a user in the first domain name; the second domain name server obtaining a second identifier of the user in the second domain name corresponding to the cross-domain user identifier, and generating a user login state of the user in the second domain name according to the second identifier, characterized in that wherein before the step of a second domain name server obtaining a cross-domain jump request of jumping from a first domain name to a second domain name sent by a browser, the method further comprises: the browser obtaining a request of jumping from the first domain name to the second domain name, and generating the cross-domain user identifier according to the second domain name and the first identifier; the browser generating the cross-domain jump request according to the cross-domain user identifier and the second domain name and sending the cross-domain jump request to the second domain name server, wherein the step of the browser generating the cross-domain user identifier according to the second domain name and the first identifier comprises: the browser finding a registered identifier and a second domain name key corresponding to the second domain name, and combining the registered identifier and the first identifier; the browser encrypting the combined identifier according to the second domain name key to generate the cross-domain user identifier. the browser obtaining a request of jumping from the first domain name to the second domain name, and generating the cross-domain user identifier according to the second domain name and the first identifier; the browser generating the cross-domain jump request according to the cross-domain user identifier and the second domain name and sending the cross-domain jump request to the second domain name server, wherein the step of the browser generating the cross-domain user identifier according to the second domain name and the first identifier comprises: the browser finding a registered identifier and a second domain name key corresponding to the second domain name, and combining the registered identifier and the first identifier; the browser encrypting the combined identifier according to the second domain name key to generate the cross-domain user identifier. the browser finding a registered identifier and a second domain name key corresponding to the second domain name, and combining the registered identifier and the first identifier; the browser encrypting the combined identifier according to the second domain name key to generate the cross-domain user identifier.