Abstract: The paper studied control effect of 6% Thiram-tebuconazole-cypermethin suspension concentrates for seed dressing with the treament of 857 mg,1000mg /kg seeds and 1200 mg/kg seeds on maize head smut.The results showed that control effect reached 72.6%～81.1%,control effect of compound pesticid was higher than that of single use of each pesticid,the recommended dosage of control maize head smut was 857～1000mg/kg seeds（effective content）in production.