A　small　amount　of　mineralizer　MgO　was　added　into　Al2TiO　5　synthesized　from　the　sludge　of　aluminum　factory　to　form　Al　2-xMgx+yTi1-yO5-0.5x-y　solid　solution　and　inhibit　the　decomposition　of　Al2TiO5　solid　solution.　It　increased　the　content　of　Al2TiO5　solid　solution　and　improved　the　thermal　stability　of　materials.　In　this　work,　XRD　and　SEM　methods　were　adopted　to　characterize　the　crystalline　structure　and　microstructure　of　each　kind　of　sample.　Rietveld　Quantification　method　was　used　to　determine　the　content　of　crystalline　phases　in　each　sample.　Results　show　as　follows:　the　optimal　addition　concentration　of　MgO　was　2.0%,　and　the　corresponding　content　of　Al2TiO5　solid　solution　which　displayed　irregular　bulk　shape　was　100%;　the　addition　of　mineralizer　MgO　could　enhance　the　flexural　strength　and　thermal　stability　of　Al2TiO　5　solid　solution　materials.　The　optimal　addition　concentration　of　MgO　determined　by　performance　analysis　was　2.0%,　and　its　corresponding　retention　rate　of　thermal-shock　flexural　strength　was　86.4%.　Structure　analysis　and　performance　analysis　resulted　in　good　accordance.