Abstract: In order to clarify the bioactivity of fluazinam to Fusarium pseudograminearum, the mycelial growth of 86 strains of F. pseudograminearum isolated from various cities in Henan Province from April to May 2022 was determined. The sensitivity baseline was established, and the field control efficacy of fluazinam on Fusarium crown rot (FCR) was determined. The results showed that the minimum inhibitory concentration of fluazinam on mycelial growth was 20 μg/mL, the effective concentration (EC₅₀) of fluazinam on the mycelial growth of 86 strains was 0.013-0.492 μg / mL, and the average EC₅₀ was 0.194 μg/mL. The sensitivity of 57 strains ( 66.3%) was approximately normal distribution, and the average EC₅₀ value of 0.201 μg/mL was used as the sensitivity baseline of F. pseudograminearum to fluazinam. The sensitivity of strains in the same city was quite different, and the ratio of the maximum and minimum EC₅₀ was 2.8-36.7. The difference in Luohe was the largest, and the difference in Xuchang was the smallest. There was no significant difference in the sensitivity of strains to fluazinam in different cities, and the EC₅₀ of fluazinam to Shangqiu strains was 1.75 times that of Zhumadian strains, indicating that Zhumadian strains were the most sensitive and Shangqiu strains were the least sensitive. There was no significant correlation between the sensitivity of F. pseudogramine to fluazinam and the geographical origin of the strains in Henan Province. There was no significant correlation between the sensitivity to fluazinam and its sensitivity to carbendazim and tebuconazole. Seed soaking with 500 g/L fluazinam suspension concentrate (SC), the incidence of FCR in Yichuan County and Xin 'an County decreased by 45.46% and 56.88%, respectively, at the double ridge stage, and the white spike rate decreased by 8.73% and 13.67%, respectively, at the milky stage. The control efficacy of seed soaking with 500 g/L fluazinam SC against FCR of wheat at the double ridge stage was better, reaching more than 51% in both places. This study laid a theoretical basis for the prevention and control of fluazinam in FCR.