Selective laser melting (SLM) technology is an ideal process for preparing complex lattice structures because of its unique forming principle. The effects of heat treatment on microstructure, mechanical properties, fracture mechanism and energy absorption characteristics of titanium alloy skeleton and sheet structure were analyzed by numerical simulation and experiment. The results show that the α + β phase is evenly distributed in titanium alloy after solution aging heat treatment, and the α' phase martensite gradually decreases and β phase increases with the increase of solution temperature. Under different heat treatment conditions, the compression strength of sheet structure is 1.81~2.17 times that of skeleton structure, and the stress of platform is 3.1 times that of the latter, but the elastic modulus of the two is similar. At the same time, the heat treatment process has little effect on the mechanical properties of the skeleton structure and great effect on the sheet structure. Both types of structures show the phenomenon of 45° diagonal shear fracture and fracture zone transfer. The energy absorption efficiency of the skeleton structure is much higher than that of the sheet structure, but the accumulated energy absorption amount is low. The heat treatment process does not improve the energy absorption performance of the measured structure.