Multi-beam selective laser melting (SLM) has been adopted to enhance the production rate and to enable the production of parts with dimensions exceed the layout of traditional single-beam SLM apparatus. Several overlapping methods can be applied to connect different scanning zones to form a large scanning layout, in the meantime the forming qualities of the components are affected by the overlap methods due to different melting/solidification behaviors in the overlap zones. In this paper, two kinds of overlap methods were designed: direct overlap and interleave overlap, to study the effect of overlap methods on the forming qualities, both the forming precision of top surface and metallurgical defects in overlap zones were analyzed. The results show that the join interfaces in the interleave overlap samples are alternative with each other in different layers, thus the ill bonding defects can be suppressed and the remelting effect from the repeating laser scanning can be effectively controlled; interleave overlap method is better for the forming of dense components with high precision when compared with direct overlap method.