Litchi (Litchi chinensis Sonn.) is one of the important tropical and subtropical fruits in China. However, litchi downy blight caused by the infection of Peronophythora litchii (Peronophythora litchii Chen ex Ko et al.) a severe disease damaging litchi during production, storage, and transportation, seriously threatening the healthy development of China’s litchi industry. Objective We screened effective antagonistic bacteria against P. litchii and evaluated their plant growth-promoting potential, aiming to enrich the resources of antagonistic bacteria against P. litchii. Methods Soil samples from the litchi rhizosphere were collected, and the bacteria in the samples were isolated through a high-throughput isolation and culture method. The strains were identified by means of 16S rRNA gene sequence analysis. The antagonistic strains against P. litchii were screened via the plate confrontation method, and the plant growth-promoting functions [phosphorus solubilization, potassium solubilization, nitrogen fixation, siderophore secretion, and indole-3-acetic acid (IAA) production] of the antagonistic strains were further evaluated through functional plates. Results A total of 327 bacterial strains were isolated in this study, among which 92 (28.13%) strains were identified as antagonists (with mycelial growth inhibition rates>40%) against P. litchii. These antagonistic strains belonged to 4 phyla, 6 classes, 12 orders, 20 families, and 42 genera, with Bacillota and Pseudomonadota being the dominant phyla, and Bacillus and Paenibacillus as the dominant genera. Functional evaluation of the 92 antagonistic strains revealed that 55 (59.8%) strains exhibited more than one plant growth-promoting function, while 30 (32.6%) strains possessed three or more such functions. Through comprehensive evaluation of antagonistic activity and plant growth-promoting functions, one Brevibacillus strain T101, four Paenibacillus strains (T431, T270, T327, and T234a), and one Paraburkholderia strain R116b were identified as the most promising strains for biocontrol applications. Conclusion Multiple antagonistic strains against P. litchi,with functions of phosphorus solubilization, potassium solubilization, nitrogen fixation, siderophore secretion, and IAA production, are screened out, which provides efficient strain resources for the green control of litchi downy blight.