To address the large error and low efficiency of traditional manual design in cable laying task,the computer-aided design optimized by Ant Colony Algorithm (ACA) is applied to cable laying path planning.The shortest path for cable laying is solved via the ACA's multi terminal path calculation for complex path planning.Furthermore,the planarized cable laying path is optimized via Gompertz function in aspects of pheromone restriction and self-adaptive adjustment of volatilization factor,thus improves the ACA in both convergence speed and global performance.The simulation results show that the optimized ant colony algorithm can quickly obtain the shortest cable laying path in the task of substation digital 3D cable laying,which saves the cost of manpower and materials,and improves the design accuracy.