Topology　optimized　porous　lattice　structure　with　different　unit　cell　sizes　(1~6　mm)　and　porosities　(40~80%)　were　fabricated　by　Selective　Laser　Melting,　and　their　compressive　deformation　behavior　and　elastic　properties　were　discussed.　The　results　show　that　compressive　strength　and　elastic　modulus　of　lattice　structure　were　inversely　proportional　to　unit　cell　size.　Their　compressive　strength　ranged　from　126　to　199　MPa　and　elastic　modulus　ranged　from　3.5　to　55.47　GPa.　The　stress-strain　curves　of　lattice　structures　with　different　unit　cell　sizes　followed　three　kinds　of　stress-strain　laws:　elastic　material,　elastic-brittle　material　and　brittle　material.　The　compressive　deformation　process　simulated　by　ABAQUS　explained　the　reason　of　two　45°　fracture　band.　The　numerical　results　show　a　good　agreement　with　experimental　results.　The　stability　was　evaluated　by　Gibson-Ashby　model,　and　the　stability　parameter　C　decreased　with　the　increase　of　unit　cell　size.　Meanwhile,　the　fitting　curves　based　on　Gibson-Ashby　model　were　established,　and　the　value　of　n　increased　with　the　increase　of　unit　cell　size.　A　3D　surface　mathematical　model　combining　unit　cell　size,　relative　density　and　relative　elastic　modulus　was　established,　and　the　design　area　satisfying　mechanical　properties　of　bone　implants　was　proposed.　©　2020,　Science　Press.　All　right　reserved.