Fe2-xAlx(MoO4)3(x=0,0.2,0.4,0.6,0.8,1.0,1.2,1.4,1.6,1.8,2.0) powder samples of monoclinic Fe2(MoO4)3 to monoclinic Al2(MoO4)3 solid solution series were prepared by the sol gel method. Through X-ray diffraction,it has been found that all samples had the same monoclinic phase structure,no phase structure separation occurred,the coexistence of Fe2-xAlx(MoO4)3 in differ-ent proportions was successfully achieved. The crystal cell volume of monoclinic Fe2(MoO4)3 is decreased with increasing aluminum con-tent,which is related to the entry of Al3+instead of Fe3+. The x=1.6 composition fired at 600℃ showed the best reversible thermochro-mic performance,the inorganic reversible thermochromic materials have the characteristics of continuous discoloration with temperature. In this paper,the theoretical mechanism of the interaction between the chromophore ions in the molybdate matrix will be explained to fur-ther improve the controllable regulation preparation and application of new thermochromic materials.