The low heat solid state reaction method for the synthesis of functional material lanthanum phosphate was studied,and the target product was obtained successfully with La(NO3)3·6H2O and(NH4)3PO4·3H2O as raw materials and PEG-400 as surfactant via the low heat solid state reaction.Crystallization calculated with XRD data of the product was used as the testing index,and application of uniform experimental design as well as data mining technology were used in the test.The synthesis tests were performed under the guidance of the results of data mining technology.The test results indicated that the product synthesized with the optimal technical condition was LaPO4·0.5H2O with the size of 23 nm and crystallization of 97.8%.TG/DTA analysis results indicated that LaPO4 could be obtained from dehydration of LaPO4·0.5H2O at 300℃.