The invention belongs to the technical field of the database, and particularly relates to a data synchronization method. The data synchronization method based on an oracle database comprises the following steps of: exporting business related data by a host, and sending the business related data to a standby machine importing database; scanning a database log on the host; recording data variation to a local log file; compressing and sending the local log file to the standby machine; and after the standby machine receives synchronized data, analyzing into the local log file which is consistent with the host data. When the host fails, the logic states of the host and the standby machine are revised by a control program, and the standby machine replaces the host to continue to work. If the host fails to cause host communication faults, the standby machine is directly operated by the control program to be forcedly switched into the host, so as to continuously support the system to operate. According to the data synchronization method based on the oracle database, which is disclosed by the invention, data synchronization service is independent from a service program, the service program design complexity is lowered, a transmission channel is uniformly managed, and the data synchronization method based on the oracle database is suitable for special requirements, such as the encryption and decryption processing of the data channel.