The Guangzhou Digital Education City has been set up by the Education Department of Guangzhou, and the application system of each school can be integrated through SSO to realize the sharing of higher level resources. But because the actual situation of each school is quite different, the integration process is bound to have some objective problems. This paper discusses on some special problems that may be encountered in the access of Guangzhou Digital Education City SSO system in secondary vocational schools, especially on how to realize heterogeneous docking for the schools which have its own SSO system, and puts forward a good solution for the actual situation.