The　use　of　industrial　semicoke　ash　as　skeleton　material　is　proposed　in　this　study　to　fabricate　low-cost　thermal　energy　storage　materials　and　shape-stable　phase　change　composites　as　well　as　recycle　industrial　solid　waste　for　building　heating.　Eight　samples　with　different　mass　ratios　of　semicoke　ash　to　NaNO3　are　manufactured.　Key　performance　of　NaNO3/semi-coke　ash　shape-stable　phase　change　composite　is　then　investigated　using　differ-ential　scanning　calorimetry,　laser　flash　analysis,　scanning　electron　microscopy,　X-ray　diffraction,　and　constant-speed　pressurization　method.　Results　showed　that　the　sample　CC2　with　a　mass　ratio　of　semicoke　ash　to　NaNO3　of　5:5　demonstrates　the　absence　of　visual　leakage　and　deformation　and　reaches　a　maximum　thermal　energy　storage　capacity　of　325.91　J/g　in　the　range　of　100　degrees　C　to　380　degrees　C,　mechanical　strength　of　96.98　MPa,　and　maximum　thermal　conductivity　of　1.004　W/(m　center　dot　K).　In　addition,　semicoke　ash　is　chemically　compatible　with　NaNO3.　Both　thermal　energy　storage　capacity　and　thermal　conductivity　of　sample　CC2　increase　slightly　after　4027　heating/　cooling　cycles.