This is a multicenter, randomized, double-blind, placebo-parallel-controlled, two-stage design, Phase II clinical study. This study is divided into two stages. Stage 1 (Phase IIa) has a dosing duration of 24 weeks (treatment period of 28 weeks) and aims to preliminarily evaluate the efficacy, safety, PK characteristics, and immunogenicity of XKH001 Injection in trial participants with moderate to severe COPD. Stage 2 (Phase IIb) has a dosing duration of 48 weeks (treatment period of 52 weeks) and aims to further evaluate the efficacy, safety, PK characteristics, and immunogenicity of XKH001 Injection in trial participants with moderate to severe COPD.