The invention provides a prefabricated concrete comprehensive pipe gallery stable waterproof device and method, and belongs to the technical field of municipal engineering. According to the prefabricated concrete comprehensive pipe gallery stable waterproof device, and C-shaped steel, C-shaped grooves, outer side horizontal partial pressure plates, outer side horizontal pressure bearing plates andfirst grooves are separately formed in concrete plate sheets, on the upper parts and the lower parts, of a joint of two comprehensive pipe galleries. Inner side horizontal partial pressure plates andinner side horizontal bearing plates are arranged in the first grooves, a plurality of I-shaped steel, a plurality of I-shaped grooves, a plurality of vertical partial pressure plates and a pluralityof vertical pressure bearing plates are separately arranged on concrete plate sheets, on the left side and the right side, of the joint of the two comprehensive pipe galleries, second grooves are formed in the inner walls of the concrete plate sheets, and the vertical pressure bearing plates are arranged on the inner side of the second grooves. According to the prefabricated concrete comprehensive pipe gallery stable waterproof device and method, differential settlement can be prevented from occurring to the pipe galleries, the sealed waterproof effect is realized, the integral strength of the comprehensive pipe galleries is improved, the structure is simple, the construction speed is high, and economic performance and environmental protection are achieved.