The fracture process of human bone under impacting is accompanied by the absorption of energy. The design of porous implant should consider compressive behavious and energy absorption characteristics of the whole structure. A series of lattice structures with different unit cell size and relative density is established by topology optimization designing and laser additive manufacturing fabricating, and the suface quality, fracture and deformation regularity and energy absorption performance of lattice structure are investigated by melt pool monitoring, unidirectional compression test and finite element simulation. The results show that the structure parameters of lattice structure are affected by the temperature field of molten pool and the supporting force of powder layer. The compressive behavious of lattice structures follows the law of elasticity and brittleness foam, the crush band forms at an angle of 45o with the fabricating direction. The fracture mechanism of lattice structure is ductile fracture, and the crack propagation direction is distributed along the internal micro-pores. The energy absorption capacity is directly proportional to the relative density and inversely proportional to unit cell size. The energy absorption efficiency is inversely proportional to the relative density and proportional to the cell size.