In order to improve the seed quality of Brassica oleracea and reduce the incidence of seedling diseases,this study investigated the effects of different concentrations of hymexazol and metalaxyl-M·fludioxonil seed coating agents on seed germination,seedling growth,and disease occurrence of Brassica oleracea.The results showed that the seed germination potential,seed germination rate,and emergence rate of two Brassica oleracea varieties showed a trend of first increasing and then decreasing after being mixed with the same pesticide at different concentrations.When the concentration of hymexazol seed coating agent is 0.10%,the seeds germination potential and seeds germination rate were higher than other concentrations of hymexazol seed coating agent treatments;The germination potential and germination rate of the seeds treated with 3 mL·kg-1 metalaxyl-M·fludioxonil seed coating agent were higher than those treated with other concentrations of metalaxyl-M·fludioxonil seed coating agent,and it was also the most effective among all treatments.The research results provide important reference and guidance for the high-quality seed processing technology of Brassica oleracea.