Ship pipeline path planning is susceptible to problems such as local optima and path redundancy. To solve these issues, this paper adopted the blocked-path pruning A* algorithm (BPA-star) to study pipeline layout optimization. After establishing the geometric model of the pipeline working space, the algorithm was improved by integrating pruning segmentation and blocked-path iteration techniques. This method not only avoids the local optimum trap of traditional search algorithms and expands the global search range, but also eliminates redundant routes and unnecessary turning points, thereby effectively improving the quality of pipeline planning. The results show that for single-pipeline cases, the BPA-star algorithm achieves optimal values in terms of path length, number of turns and energy cost. For multi-pipeline cases, it produces a more compact layout that fits the hull structure well. Compared with the conventional A* algorithm, the proposed method delivers better pipeline connection performance, along with superior economic efficiency and adaptability. Without the directional guidance of extension segments, the energy value of pipelines planned by the algorithm decreases by 45.68%, and the installation adaptation length increases by 400%. With the directional guidance of extension segments adopted, the number of pipeline turns decreases by 8.64%, and the installation adaptation length increases by 54.64%. The findings can provide guidance for ship pipeline layout design and have practical application value for improving pipeline design and construction efficiency.