The invention relates to the technical field of computers and discloses a synchronization method and system. The method comprises the steps of registering the data type and the data operation of data needing synchronization and events, establishing corresponding event notice when corresponding data operation of the data in the registered data type exists, handing out established notice to corresponding events according to the data operation, checking all the events corresponding to the data operation in the notice, establishing corresponding synchronous execution events or asynchronous execution events, executing the synchronous execution events or the asynchronous execution events, recording information relevant to the asynchronous execution events if the asynchronous execution events are executed, and returning to corresponding results after completion of execution. The synchronization method and system can achieve the purpose of the data uniformity of synchronous task and solve the problem of the conflict problem caused by simultaneous data modification by two systems.