The present invention discloses a strain of Streptomyces silaceus PAPM18, which has been preserved in the General Microbiology Center of China Microbiological Culture Collection Management Committee on July 4, 2018, and its biological preservation number is: CGMCC NO.16054 . The strain can survive in saline-alkali soil, and has a good degradation effect on plant autotoxic substances such as phenylacrylic acid, p-hydroxybenzoic acid, and ferulic acid, and can reduce continuous cropping obstacles caused by them. Promote growth and increase yield. After expanding the culture, the strain was inoculated in a medium with cornstarch and corn steep liquor as the main nutrient source, cultured at 35-37°C for 72-96h, and then trehalose, molasses and biological fulvic acid powder were added to the fermentation broth, and then The live bacteria preparation can be obtained by spray drying. The preparation method of the microbial preparation is scientific, the fermentation period is short, the fermentation liquid bacterial concentration is high, the loss of live bacteria is small in the spray drying process, and the stability of the live bacteria preparation is high in the preservation process.