The invention relates to citrus endophytic actinomycetes with antibacterial activity on various plant pathogens, belonging to the technical field of microbes. The endophytic actinomycetes are Streptomyces sp. R1020 which was registered and collected in China General Microbiological Culture Collection Center on March 17, 2014 with the collection number of CGMCC No. 8923. The strain R1020 has relatively good inhibitory effect on citrus anthrax bacteria, citrus bacterial canker disease bacteria, citrus penicillium italicum, citrus penicillium digitatum, bayberry deadwood disease bacteria, bayberry acicola, bayberry anthrax bacteria, loquat anthrax bacteria, loquat leaf spot fungi, loquat ringspot pathogenic bacteria, tomato alternaria solani, botrytis cinerea, colletotrichum orbiculare, tea tree anthrax bacteria and elsinoeleucospila and has the potential of being developed into biological pesticides.