The multi-layer Morphin algorithm extends the prediction range of the unknown environment and overcomes the shortcomings of the traditional Morphin algorithm′s invisible search trajectory. However, the number of search arcs generated by each search node is fixed, and the time spent searching and evaluating varies with the number of search layers. The increase is exponentially increasing. Aiming at this problem, a variable search arc of Morphin (VSAMorphin) is proposed. The number of search arcs generated by each search node is adjusted so that it is no longer fixed, but decreases as the number of layers increases, thereby shortening the search and evaluation time. The simulation results of MATLAB show that the multilayer VSAMorphin algorithm is basically consistent with the path planned by the multilayer Morphin algorithm, but the running time is relatively less, thus verifying the validity and correctness of the multilayer VSAMorphin algorithm.