Abstract: In order to study the effects of different offset ratios on the mechanical properties of the arch lattice, 12 AlSi10Mg arch lattice samples with different offset ratios were formed by selective laser melting technology. Quasi-static compression tests were conducted to analyze the effects of offset ratios on the compressive strength and elastic modulus of the lattice. Combined with finite element simulation and compression test, the influence of the change of stress concentration on the failure mode of arch lattice with different offset ratios was analyzed. The results show that the compressive strength and elastic modulus of the arch lattice reach the maximum value when the offset ratio is 20%, and the compressive strength and elastic modulus of the arch lattice are increased by 49% and 28%, respectively. With the increase of the offset ratios, the stress concentration of the lattice first diffuses from the node to the member at both ends of the node, and the failure form of the lattice changes from layer by layer collapse to shear fracture. At this time, the increase of the offset ratios has a strengthening effect on the node of the lattice, and then there is a trend of concentration to the node, and the central stress of the node gradually decreases, and the failure form of the lattice changes from shear fracture to shear fracture with the collapse of the node. At this time, the increase of the offset ratios weakens the node strength of the lattice.