The　function-graded　NiTi　part　is　one　of　the　greatest　potential　smart　materials　due　to　its　superelasticity,　shape　memory,　biocompatibility　and　the　ability　of　coupling　complex　functionality.　Laser　powder　bed　fusion　(LPBF)　is　a　promising　method　for　the　preparation　of　microstructure-gradient　NiTi　parts.　The　microstructure　of　the　NiTi　alloy　prepared　by　LPBF　was　tailored　by　switching　the　heat　transfer　modes　through　the　variation　of　the　process　parameters.　The　LPBF-fabricated　NiTi　alloy　with　fine　grains　is　obtained　in　the　conduction　mode　because　the　laser　energy　is　enough　to　melt　the　powder　while,　the　growth　of　the　grains　is　restricted　without　enough　power.　In　comparison,　the　coarse　grains　penetrating　through　two　or　more　layers　is　obtained　in　the　keyhole　mode,　due　to　the　appearance　of　the　keyholes　reheating　the　previous　layers.　This　work　proved　the　feasibility　for　the　preparation　of　microstructure-gradient　NiTi　alloys　by　LPBF.