Abstract: Abstract：【Objective】The root rot disease of the Phoenix regia caused by Ganoderma multipileum has been worsening in recent years，This study aims to screen for biocontrol strains with high efficacy against Delonix regia root rot, providing new strain resources for the green control of this disease.【Method】Two strains, FH-3 and FH-7, with excellent control effects on Delonix regia root rot were screened out through plate standoff experiments, and identified, optimized for fermentation and tested for potting efficacy. 【Result】The inhibitory rate of the mixed bacterial strain FH-3 and FH-7 against Ganoderma multipileum was 72.8%. Through morphological and molecular identification, strain FH-3 was identified as Pseudomonas aeruginosa, and strain FH-7 as Bacillus licheniformis. In pot experiments, the relative efficacy of the mixed bacterial strain against Delonix regia root rot was 79.09%. Through single-factor and orthogonal experiments, the optimal culture medium for the FH-3 and FH-7 mixed bacterial strain was determined to be 3% sucrose, 0.5% ammonium sulfate, 1% beef extract, and 2% potassium chloride; The optimal fermentation conditions were a temperature of 32℃, initial pH of 7, inoculum concentration of 3%, incubation time of 24 hours, and stirring speed of 220 rpm. After optimization, the mixed bacterial strain achieved a pathogen inhibition rate of 88.7%.【Conclusion】The mixed strain of FH-3 and FH-7 can effectively prevent and control root rot caused by Phoenix regia covering Ganoderma multipileum, providing a theoretical basis for the subsequent development and application of biological control agents.