The invention relates to construction of factory building equipment foundations, in particular to a method for the construction of large-area factory building equipment foundations. The method for closed construction of large-area factory building equipment foundations comprises the following: a step of supporting column foundations or existing structures; a step of mounting steel structures; a step of mounting and precontrolling rails; a step of precipitation for blocks of the equipment foundations; a step of excavating earthwork for the equipment foundations by a closed bunker-jump method; a step of structural closed construction for the equipment foundations by a bunker-jump method; a step of precontrolling and adjusting the thin part of a steel structure; and a step of mounting equipment and protecting finished products. The method for closed construction greatly saves the construction investment, facilitates the construction, and well ensures the safety and the normal production of the existing structures and the equipment.