In this study，the high-efficiency phosphate-solubilizing strains screened and isolated from soil were used as the research object，and the insoluble phosphorus source medium and soil pot were selected as the research objects to explore the dissolution of insoluble phosphorus sources by phosphate-solubilizing strains and the improvement effect on soil available phosphorus. The aim was to provide strain resources and theoretical basis for the subsequent development of specific and efficient phosphate-solubilizing bacteria. The results showed that a high-efficiency phosphate-solubilizing strain NP was isolated from soil. In the inorganic phosphorus medium with calcium phosphate as phosphorus source，obvious phosphorus-dissolving ring was produced. The strain was identified as Penicillium oxalicum. The strain was cultured in insoluble phosphorus culture medium with ammonium nitrogen and nitrate nitrogen as nitrogen sources at 30℃ for 7 days，which could dissolve insoluble phosphorus and increase soluble phosphorus concentration. When the strain was applied to azalea flower pots，it increased soil available phosphorus by 63% and increased by 316 mg/kg in 20 days. In abandoned pot soil，it could increase available phosphorus by 236% and increase by 144 mg/kg in 20 days. In summary，Penicillium oxalicum strains could dissolve insoluble phosphorus and effectively improve soil available phosphorus.