Incineration　is　a　harmless　way　to　treat　municipal　sludge.　However,　it　is　difficult　to　fix　heavy　metals　in　the　sludge-incinerated　ash　(SIA).　To　fix　the　heavy　metals　and　recycle　the　SIA　effectively,　this　work　innovatively　proposed　the　SIA　as　skeleton　material,　and　five　shape-stable　phase　change　composites　(SSPCCs)　with　dif-ferent　mass　ratios　of　SIA　to　NaNO(3　()phase　change　material,　PCM)　were　fabricated　via　the　cold-compression　&　hot-sintering　(CCHS)　method.　Then,　key　thermal　performance,　mechanical　strength,　and　micro-morphology　were　investigated　while　the　chemical　compatibility　between　the　SIA　components　and　NaNO3　was　analyzed.　Results　showed　that　the　SSPCCs　could　fix　the　heavy　metals　properly,　and　the　SIA　was　suitable　for　skeleton　material;　The　SSPCC　with　the　mass　ratio　5:5　of　SIA　to　NaNO3　reached　a　maximal　thermal　energy　storage　(TES)　density　of　409.25　kJ/kg　in　the　range　of　100-400　degrees　C,　which　had　high　mechanical　strength　of　139.65　MPa　and　good　thermal　stability;　The　SIA　components　demonstrated　excellent　chemical　compatibility　with　NaNO3.　(C)　2022　Institution　of　Chemical　Engineers.　Published　by　Elsevier　Ltd.　All　rights　reserved.