Magnesium　phosphate　cement　offers　high　strength,　excellent　temperature　resistance,　alongside　superior　bonding　properties;　but　its　high　density,　substantial　carbon　emissions,　and　instability　in　foaming　processes　restrict　its　applications　in　thermal　insulation　and　fire　protection.　This　study　employed　natural　brucite　and　ammonium　dihydrogen　phosphate　as　the　base　materials　for　magnesium　phosphate　cement,　while　magnesium　carbonate,　sodium　bicarbonate,　or　sodium　dodecyl　sulfate　(SDS)　were　used　as　foaming　agents　to　prepare　porous　brucitebased　magnesium　phosphate　cement　(BMPC).　The　study　focused　on　investigating　the　physical　and　mechanical　properties,　thermal　conductivity,　and　microstructure　of　the　BMPC.　The　results　indicate　that,　within　the　same　density　range,　magnesium　carbonate-modified　BMPC　has　the　least　impact　on　mechanical　properties,　while　the　thermal　conductivity　can　be　reduced　by　46.6　%　and　the　thermal　diffusivity　by　110.4　%.　The　results　indicate　that,　within　the　same　density　range,　magnesium　carbonate-modified　BMPC　has　the　least　impact　on　mechanical　properties,　the　proportion　of　small　and　medium　pores　increases,　and　the　fractal　dimension　is　the　lowest.　BMPC　offers　advantages　such　as　lightweight,　thermal　insulation,　and　low　carbon　emissions.