A service provisioning method in an internet protocol IP multimedia subsystem IMS, realized through configuring a provisioning transaction management entity in the IMS, wherein provisioning information required by various network elements in the IMS during a provisioning process of a designated IMS service is stored in the provisioning transaction management entity, and the provisioning information comprises: user data obtained from the service support system in the IMS, data obtained from a telephone number mapping ENUM server or a domain name server DNS, and service information obtained from an application server AS; the method comprising: during a service provisioning process, the provisioning transaction management entity receiving query requests of various network elements in the IMS; and the provisioning transaction management entity sending provisioning information corresponding to the query requests to the various network elements; wherein before the step of the provisioning transaction management entity sending provisioning information corresponding to the query requests to the various network elements, the method comprises: when a user initiates a service provisioning request, the service support system provisioning the user data to the provisioning transaction management entity (Step 101, S902); the service support system provisioning the data obtained from the ENUM server to the provisioning transaction management entity (Step 102, S904); the service support system provisioning the service information obtained from the AS to the provisioning transaction management entity (Step 103, S906). user data obtained from the service support system in the IMS, data obtained from a telephone number mapping ENUM server or a domain name server DNS, and service information obtained from an application server AS; the method comprising: during a service provisioning process, the provisioning transaction management entity receiving query requests of various network elements in the IMS; and the provisioning transaction management entity sending provisioning information corresponding to the query requests to the various network elements; wherein before the step of the provisioning transaction management entity sending provisioning information corresponding to the query requests to the various network elements, the method comprises: when a user initiates a service provisioning request, the service support system provisioning the user data to the provisioning transaction management entity (Step 101, S902); the service support system provisioning the data obtained from the ENUM server to the provisioning transaction management entity (Step 102, S904); the service support system provisioning the service information obtained from the AS to the provisioning transaction management entity (Step 103, S906). during a service provisioning process, the provisioning transaction management entity receiving query requests of various network elements in the IMS; and the provisioning transaction management entity sending provisioning information corresponding to the query requests to the various network elements; wherein before the step of the provisioning transaction management entity sending provisioning information corresponding to the query requests to the various network elements, the method comprises: when a user initiates a service provisioning request, the service support system provisioning the user data to the provisioning transaction management entity (Step 101, S902); the service support system provisioning the data obtained from the ENUM server to the provisioning transaction management entity (Step 102, S904); the service support system provisioning the service information obtained from the AS to the provisioning transaction management entity (Step 103, S906). when a user initiates a service provisioning request, the service support system provisioning the user data to the provisioning transaction management entity (Step 101, S902); the service support system provisioning the data obtained from the ENUM server to the provisioning transaction management entity (Step 102, S904); the service support system provisioning the service information obtained from the AS to the provisioning transaction management entity (Step 103, S906).