The invention discloses a weighing method of a large ocean function module. The weighing method of the large ocean function module comprises the following steps that A, according to structural style characteristics and tonnage of a generator module, 12 independent weighing units are selected to weigh the generator module; B, the 12 independent weighing units are arranged on the designated position of the generator module; C, the generator module is wholly ejected by 10mm through 12 hydraulic lifting jacks, after numerical reading in a data display is recorded, the 12 lifting jacks are decompressed, and then are repeated ejected twice, and statistics of the numerical reading is conducted; D, three-time numerical reading is respectively conducted analysis processing, a torque balance principle is utilized to respectively compute the gravity center place of the generator module. The weighing method of the large ocean function module can save a large amount of manpower and resources, shortens a ship construction period, simultaneously achieves synergia aim, lays a solid foundation for improving safety and accuracy of lifting of the module, reducing harmful factors, and preventing overweight conditions of the ship in the process of lifting of the module from occuring and has popularization value in China.