Abstract: 【Objective】Silkworm excrement is not only rich in nutrients, but also a variety of functional microorganisms. In this study, in order to provide resources for the development and utilization of microbial fertilizer, some high efficient phosphate dissolving bacteriawere screened and its phosphate dissolving mechanism was discussed preliminarily.【Method】A high temperature resistant strain with high efficiency of inorganic phosphorus hydrolysis was screened from the silkworm excrement through the inorganic phosphorus screening medium, and classified using the methods of physiology, biochemistry and molecular biology;the soluble phosphorus and the organic acid contents were quantitatively determined by the methods of the molybdenum antimony anti colorimetry and the high performance liquid chromatography(HPLC), respectively. The relevant data was statistical analyzed by the SPSS statistics software.【Result】A strain was screened from silkworm excrement during high temperature composting fermentation. The strain was white round colony, rod-shaped and gram positive. Full-length genome sequence was obtained by genome sequencing. The genome size was 5324477 bp, GC content was 37.73%, 37 Scaffolds, 73 Contigs, a total of 5628 genes were predicted along with 48 tRNAs and one rRNA. It was classified as Bacillus megaterium, named SEM-5, which had a marked function of dissolving inorganic phosphorus and strong tolerance of salt(NaCl concentration ≤ 10%), alkali(pH 5-10) and high tempera-ture(60). The result showed that the dissolving inorganic phosphorus ability of the strain on different sources was different. The dissolution efficiency of inorganic phosphorus from calcium salt was significantly higher than that of aluminum phosphate and iron phosphate(P<0.05, the same below). The data of available phosphorus concentration, organic acid and pH of SEM-5 strain fermentation broth in different fermentation times were detected and analyzed, and correlation analysis showed that the correlation between the concentration of soluble phosphorus and different organic acids was different in different fermentation times. The concentration of soluble phosphorus in fermentation broth had an extremely significant positive correlation with the content of acetic acid and tartaric acid(P<0.01, the same below), and had a significant positive correlation with the content of lactic acid, succinic acid, propionic acid in fermentation broth, and had a extremely significant negative, significant negative correlation with pH of the fermentation broth and the content of oxalic acid, respectively, but had no significant difference with malic acid and citric acid contents(P>0.05), from the beginning to day14 of the fermentation.【Conclusion】B. megaterium isolated from silkworm excrement(strain SEM-5) has good environmental adaptability, including tolerance to salt, alkali and high temperature, and exhibits a good dissolving and releasing ability for inorganic phosphorus from insoluble calcium source. It has a good application potential and development value of microbial fertilizer.