1. A file synchronization method, wherein the file synchronization method is applied in a hybrid system which has a first system and a second system, the method comprising steps of: monitoring, by the first system, a first cache of the first system, in which first data corresponding to a first file stored in a non-volatile storage of the first system opened by a first file processing program of the first system is saved; sending, to the second system, operating content performed by the first file processing program on the first file via a data information channel between the first system and the second system, when the first data in the first cache is changed; and performing a synchronization processing on a second file by a second file processing program in the second system according to the operating content, the second file being a file corresponding to the first file in the second system and being stored in a non-volatile storage of the second system, such that the second file is updated in real time to be consistent with the changed first data in the first cache, wherein the first system comprises a first plug-in application service logic configured for: recording structure parameters of the first file and the operating content performed by the first file processing program on the first file; establishing and maintaining a data information channel with a second plug-in application service logic in the second system; and sending to a second plug-in application service logic in the second system the operating content performed on the first file and/or the structure parameters of the first file; and wherein the second system comprises a second plug-in application service logic configured for: recording structure parameters of the second file and the operating content performed by the second file processing program on the second file; establishing and maintaining a data information channel with the first plug-in application service logic in the first system; and sending to the first plug-in application service logic in the first system the operating content performed on the second file and/or the structure parameters of the second file.