The invention discloses a replacement method for substation equipment based on a three-dimensional design platform. The method comprises the following steps of step 1.drawing a normative main wiring diagram and arranging the equipment; step 2.extracting ID codes of all equipment in this engineering from an engineering database, dividing according to a region of a power distribution device of the substation and then dividing in the same region of the power distribution device of the substation according to intervals to form an interval list; step 3.extracting model information of each equipment according to the interval list; step 4.selecting the interval and to-be-replaced equipment in the interval from the interval list; step 5.selecting an equipment production factory, setting screening conditions and selecting the replaceable equipment which is screened from an equipment model library; and step 6.previewing an equipment model and completing replacement. Through dividing the ID codes of the equipment to form the interval list, the equipment replacement is carried out according to the intervals, the method is convenient, quick and high in automation degree, and the design efficiency and the design quality are effectively improved.