A call method for a private branch exchange user, the method being executed in a home subscriber server for a private branch exchange user, the method comprising: receiving a data query request sent by a Call Session Control Function, wherein the data query request comprises a number of a private branch exchange user, the data query request is sent by the Call Session Control Function after the Call Session Control Function receives a call request sent by the private branch exchange user, and the call request comprises the number of the private branch exchange user; determining whether user data of the private branch exchange user comprises a flag bit, wherein the flag bit is used to indicate that the user data of the private branch exchange user is not open to the Call Session Control Function; if the user data of the private branch exchange user comprises the flag bit and the private branch exchange user has opened an account in the home subscriber server but did not register on the home subscriber server, sending a data query success response to the Call Session Control Function so that the Call Session Control Function forward the call request to an application server, wherein the data query success response comprises information about a wildcard user corresponding to the private branch exchange user; receiving a user data request from the application server, wherein the user data request comprises the number of the private branch exchange user, and the user data request is sent by the application server after the application server receives the call request forwarded by the Call Session Control Function; and sending a user data response to the application server, wherein the user data response comprises the user data of the private branch exchange user. receiving a data query request sent by a Call Session Control Function, wherein the data query request comprises a number of a private branch exchange user, the data query request is sent by the Call Session Control Function after the Call Session Control Function receives a call request sent by the private branch exchange user, and the call request comprises the number of the private branch exchange user; determining whether user data of the private branch exchange user comprises a flag bit, wherein the flag bit is used to indicate that the user data of the private branch exchange user is not open to the Call Session Control Function; if the user data of the private branch exchange user comprises the flag bit and the private branch exchange user has opened an account in the home subscriber server but did not register on the home subscriber server, sending a data query success response to the Call Session Control Function so that the Call Session Control Function forward the call request to an application server, wherein the data query success response comprises information about a wildcard user corresponding to the private branch exchange user; receiving a user data request from the application server, wherein the user data request comprises the number of the private branch exchange user, and the user data request is sent by the application server after the application server receives the call request forwarded by the Call Session Control Function; and sending a user data response to the application server, wherein the user data response comprises the user data of the private branch exchange user.