The assistance system for correcting vessel path comprises a receiver, a memory, at least one sensor, a processor and a display. The processor connects to the receiver, the memory and the at least one sensor, and the display is coupled to the processor. The assistance system based on the processor is able to be utilizing the preset machine-readable grid in determining the distance parameters of obstacles above water, and in which these distance parameters are corrected by using the sensor measurement data acquired by the at least one sensor. Thereby the assistance system could finish the distance measurements of abovementioned obstacles without using Lidar, and even in the case of high-undulating water surface.