The invention discloses bacillus amyloliquefaciens JK6 and biological fertilizer and application. The serial number of strain preservation is CGMCC No. 10658 and is stored in the China general microbiological culture collection center on March 23, 2015. The bacillus amyloliquefaciens JK6 is mainly used for biological prevention and control of pseudomonas solanacearum and is provided with an iron-production carrier, a biological membrane, protease, catalase, cellulose and IAA characteristics, multiple fungal pathogens of banana wilt pathogen, litchi anthrax germs, litchi frost phytophthora pathogens, rice blast fungus, cucumber wilt pathogen and the like, and growth of lettuce plants is obviously promoted; the K6 strain can be successfully planted, and disease preventing functional genes of yndj, srfAB, fend and ituC are expressed in soil; the strain is high in reproduction speed, simple in production technology, high in adverse resistance, easy to store and favorable for industrialized production, the biological fertilizer is prepared with the strain, soil-born diseases can be prevented and controlled, growth of the plants can be promoted, and application prospect is broad.