Abstract: The present invention relates to a method and system for correcting acquisition channel of merging unit in power system which belong to the technical field of simulation data collection of power system. The present invention performs data acquisition of each channel firstly, and the acquired data is continuous and effective frequency data, then the collected data is stored to their respective backup areas, and the data storage is stopped until the amount of stored data is up to a predetermined value required for correcting, the data is corrected finally within the respective backup areas of each channel which stops the data storage. The correction process is performed by using corresponding correction module. The method for the channel correction improves the efficiency of channel correction greatly, reduces the correction error, improves the correction precision, and has more simple and convenient operation in comparison to the conventional method for channel correction by modifying hardware parameters.