This is a multicenter, randomized, double-blind, placebo-controlled study to evaluate the effcacy and safety of 610 in adults with severe eosinophilic asthma. Subjects divided into 3 groups: A group,B group and placebo group. The study is divided into screening period of 4 weeks, treatment period of 16 weeks, prolonged treatment period of 36 weeks and follow-up period of 8 weeks.