The invention belongs to the technical field of historic building wood structure repairing, and discloses a historic building wood structure in-situ repairing method and system. The historic buildingwood structure in-situ repair system comprises a field exploration module, a data acquisition module, a data processing module, a data analysis module, a main control module, a repair positioning module, a wood structure reinforcing module, a field cleaning module, a repair plan making module, a construction repair module, a repair surface maintenance module and a repair detection acceptance module, a repair site restoration module, a data storage module, and a display module. According to the historic building wood structure in-situ repairing method, different modes are adopted for repairingin a targeted mode according to different damage conditions of the surface of a historic building wood structure, under the condition that the original wood supporting strength of a historic buildingis ensured, the use amount of wood for repairing is reduced, the required construction period for repairing the historic building is shortened, and the repairing efficiency of the historic building wood structure is greatly improved.