The invention discloses a multi-beam fine post processing method. The method includes an engineering project management module, a surveying vessel configuration module, an original data preprocessingmodule, a navigation editing module, a posture editing module, a sound velocity correction module, a tide correction module, a deep processing module, a multi-beam installation and calibration module,a three-dimensional terrain display module and a result data output module. Accordingly, the functions of data reading, file decoding, basic processing, parameter configuration, deep data editing, auxiliary parameter detection, view and display control, a help module and the like are achieved; the reference significance is achieved for an independent research and development post processing method, and meanwhile a very good promoting function is achieved for scientific research.