Abstract: Study the identity authentication protocol based on improved single sign-on system,improve the identity authentication of the speed.For the single point login system identity authentication,the user data caused by large amount of identity check long time,leading to users need to check a database of one identity information,and extended the single point login system the identity authentication of the time.In order to avoid these problems,and puts forward a kind of identity authentication protocol based on improved single sign-on system.First,the linear regression function algorithm,the user data initialized processing.And by using nonlinear transfer function will user information transmission to the server,and registration algorithm using parameters with the database data registration,and get the identity authentication,improve the identity authentication of the speed.The experiment proves that system improve the speed of the identity authentication,and satisfactory results have been obtained.