There are few kinds of fungicides for the prevention and treatment of Rhizoctonia solani,and the excessive use of chemical fungicides can cause many hazards and toxic and side effects,not in line with the requirements of rice planting. The mixed use of wood vinegar and chemical fungicides can reduce the use of chemical fungicides,alleviate pollution and improve rice quality. In this experiment,the Horsfall method was used to study the synergistic inhibiting effect of mixture between wood vinegar and chemical fungicides on the growth of Rhizoctonia solani,as well as the optimal ratio. The results showed that when wood vinegar was mixed with Captan,the synergistic mixture ratio was 4∶6,3∶ 7 or 1∶ 9,and the toxicity ratio under mixture ratio of 4∶ 6 and 1∶ 9 was 1. 75 and 1. 99,respectively,with significant synergistic effect;when wood vinegar was mixed with Chlorothalonil,the toxicity ratio(1. 08) under mixture ratio of 8∶ 2 was greater than 1,showing additive effect. There are few kinds of fungicides for the prevention and treatment of Rhizoctonia solani, and the excessive use of chemical fungicides can cause many hazards and toxic and side effects, not in line with the requirements of rice planting. The mixed use of wood vinegar and chemical In this experiment, the Horsfall method was used to study the synergistic inhibiting effect of mixture between wood vinegar and chemical fungicides on the growth of Rhizoctonia solani, as well as the optimal ratio. The results was that when wood vinegar was mixed with Captan, the synergistic mixture ratio was 4:6, 3: 7 or 1: 9, and the toxicity ratio under mixture ratio of 4: 6 and 1: 9 was 1. 75 and 1. 99, respectively, with significant synergistic effect; when wood vinegar was mixed with Chlorothalonil, the toxicity ratio (1.08) under mixture ratio of 8: 2 was greater than 1, showing additive effect.