Single sign-on method, first server and electronic equipment

The invention provides a single sign-on method, a first server and electronic equipment. The method comprises the following steps that: a sign-on request sent by the electronic equipment is received,wherein the sign-on request comprises target biological characteristic information, a first application type of a first application program to be logged in and first user account information for logging in the first application program; the first server stores the user account information of an application type corresponding to each piece of biological characteristic information, so that the firstserver can obtain the second user account information of a first application type corresponding to the target biological characteristic information, and the first server takes the biological characteristic information as an intermediate medium. The corresponding relationship between the first user account information and the second user account information does not need to be set, so that the electronic equipment logs in