The invention relates to a method, a 
system, and a browser realizing cross-domain request login. The method comprises: a first domain business 
server acquiring an 
authentication string of a second domain and writing in a cookie of the first domain after the browser is successful in 
logging in the first domain, and sending the cookie to the browser; when the browser receives an access request on the second domain, revising the 
domain name of the access request of the second domain to a dependence domain of the first domain with a second domain 
specific identification, and sending the request with the cookie of the first domain to a first domain access 
server; and the first domain access 
server determining the current request to be the access request of the second domain through 
domain name matching and recognition, acquiring the 
authentication string of the second domain from the cookie of the first domain, writing the 
authentication string into the second domain cookie, carrying the second domain cookie in the access request of the second domain, and transferring the access request of the second domain to a second domain business server. Thus, cross-domain authentication request is completed, so that a front end does not have a problem of cross-domain. The method, the 
system, and the browser are flexible to realize and are low in cost.