Aiming at the problem that traditional collision detection algorithms can’t perfectly adapt to collision detection in trajectory planning of multi-crane coordinated suspension system, a vector-based detection algorithm that comprehensively considers the collision risk of the suspension system is proposed. First, in view of the catenary effect appearing in the cable, an optimization model of the cable is proposed, and corresponding detection strategies are given according to different collision types. Then, based on the model optimization strategy, a vector collision detection algorithm and optimization method based on linear combination of points, vectors, and angles are proposed. The simulation results show that the algorithm accurately and efficiently achieves 8 effective collision detections, verifying the rationality of the optimization strategies for two different collision types. Finally, equivalent elastic strain and equivalent stress of the cables further verify that the algorithm has good collision detection accuracy and efficiency, the proposed vector collision detection algorithm can better adapt to the multi-crane coordinated suspension system in complex suspension environments and provides a feasible method reference for subsequent obstacle avoidance trajectory planning of the suspension system.