Abstract: According to the characteristics of the secondary system of substation, combined with the three-dimensional design of the primary system, the three-dimensional GIM model framework expansion, three-dimensional physical model definition, three-dimensional modeling and design application of the secondary system are studied. A scheme for the 3D design modeling rules of the secondary system of intelligent substation is proposed, which provides reference and reference for the 3D design modeling of the secondary system of intelligent substation.