Aiming at the optimization of internal hole layout in hydraulic manifold block,an optimization model was established to minimize both the length of hole pathways and pressure loss.Leveraging the structural characteristics of hydraulic manifold block,a multi-endpoint hole layout optimization algorithm based on the Rectilinear Steiner Minimal Tree(RSMT)was proposed.This algorithm transforms the three-dimensional problem of optimizing the hole pathway into a two-dimensional problem of optimizing connectivity among endpoint sets.Initially,the hole layers were assigned based on the spatial coordinates of each endpoint,and then the hole layers were merged onto the same plane.The optimization objective of the hole pathway was achieved by solving the minimum Steiner tree within the plane.The RSMT algorithm,built upon Kruskal algorithm,was employed to construct the minimum Steiner tree with right angles.Subsequently,the edges of the resulting RSMT were matched to the corresponding hole layers of endpoints,yielding the optimized overall connectivity of the hole network.The validation results from practical examples demonstrate that the layer assignment and connectivity algorithm can efficiently and effectively perform the optimization design of hole connectivity for manifold block with multi-endpoints.