This paper studied the optimal ratio screening experiments were carried out with different concentration and different treatment methods of Qianhu aqueous extract, and the effect of mixed application of 5,000 mg/L of water extract of Qianhu and 12 kinds of common Chinese herbs on rice blast resistance. The experimental results showed that Soaking the seeds with a mass concentration of 2,500 mg/L and spraying with 5,000 mg/L of the water extract of Qianhu can get a good control effect on rice blast; There were 9 kinds of Chinese herbs interacting with Qianhu, the best inducing effect of the mixture of Qianhu and tangerine peel, although there is a certain gap compared with 8% Probenazole, there is no significant difference of the efficacy durability of 8% Probenazole, and the efficacy can last for about 35 days.