The invention discloses a building method of a deep-well garage capable of serving as the foundation of a large building. The building method comprises the following steps that (1) according to the height, area and structure of the large building, the load and load distribution are calculated, and then according to the number of parking spaces, the number, distribution, sizes and depths of deep wells, the steel bar match ratios and the steel-bar concrete well wall thicknesses are determined; (2) a circle of temperature insulation holes are drilled in the position away from the outer edges of the steel-bar concrete well walls by a certain distance, then the wells are excavated in freezing circles; and (3) segmented excavation is conducted, steel-bar concrete is poured in a segmented mode to seal bottoms, meanwhile water collecting wells are reserved at the well bottoms, then steel-bar concrete is poured from bottom to top to form deep-well shaft bodies, in the pouring process, embedded parts are mounted on the well walls, and mounting grooves are reserved in the well walls. According to the building method of the deep-well garage capable of serving as the foundation of the large building, the deep-well three-dimensional parking garage is placed into the high-building basement, so that while he ground area is saved, the pile foundation building engineering of the large building is omitted, the building period is shortened, and the building cost is reduced.