In order to further clarify the role of bacteria in pine wilt disease and control effect of emamectin benzoate and antibiotic mixture on the disease，strains， which can significantly promote survival and reproduction of nematode and aggravating the disease， were screened from bacteria carried by Bursaphelenchus xylophilus. High-efficiency antibiotics were screened from 30 kinds of antibiotics by testing their antibiotic activity to the screened disease-related bacteria， and the inhibitory effect of emamectin benzoate on the disease-related bacteria was studied. The toxicity of high-efficiency antibiotics and emamectin benzoate mixture to B. xylophilus and the control effect of the mixture on pine wilt disease of 6-month-old Pinus massoniana seedlings was determined by the immersion method and the root filling method， respectively. The results showed that compared with strains AMA3-2 and AMA3-3， strain AMA3-1 had a better promoting effect on the survival， reproduction of the nematode and the disease. Ciprofloxacin and minocycline had better antibacterial activity against AMA3-1， but emamectin benzoate had no inhibitory effect on AMA3-1. When the mixture or emamectin benzoate was 500 mg/L， the mortality rate of B. xylophilus could reach more than 80%. While the corrected mortality of B. xylophilus maintained at a low level （0.74%-2.43%） under the treatment of different concentration of high-efficiency antibiotics. When the concentration was 500 mg/L， and application time was 2 days before inoculation （on the day of inoculation） with the mixture of B. xylophilus and AMA3-1， the control effect of the mixture of emamectin benzoate and high-efficiency antibiotics on the disease was 50% （25%）， while that of emamectin benzoate was 33% （17%） and high-efficiency antibiotics was 17% （0%）. The results showed that emamectin benzoate or its mixture had high toxicity to B. xylophilus， but antibiotics had no killing effect. Under certain conditions， the mixture of emamectin benzoate and antibiotic can improve the control effect on pine wilt disease.