The invention discloses a lung cancer screening kit. The lung cancer screening kit comprises an optional agent used for detecting the expression level of phosphorylation MUSK. The invention further discloses application of the agent used for detecting the expression level of phosphorylation MUSK to the preparation of the lung cancer screening agent. By detecting the expression level of phosphorylation MUSK, the kit judges the risk for lung cancer of the to-be-detected crowd, is used in the auxiliary diagnosis of clinical lung cancer, provides effective evidences for the patient to take related treatment measures or make decisions, and has an excellent clinical application prospect.