Objective To investigate the current situation of the occurrence of sarcopenia in lung cancer patients and analyze its risk factors so as to provide reference for clinical identification of the high-risk group of sarcopenia in lung cancer. Method A total of 420 lung cancer patients were conveniently selected from the First Affiliated Hospital of Guangzhou Medical University between September 2022 and July 2023. Based on the diagnostic criteria of the Asian sarcopenia working group in 2019 the study subjects were divided into sarcopenia and non-sarcopenia groups by using several indexes for joint diagnosis such as skeletal muscle index grip strength and 5 times sit - up test time. The random forest algorithm was applied to rank the importance of potential independent variables influencing sarcopenia while considering classification errors with out - of - bag data. The selected variables were subsequently incorporated into a multifactorial logistic regression analysis. Result Out of the 420 lung cancer patients 97 23. 10% exhibited coexisting sarcopenia with 47 11. 19% classified as severe cases. The results of binary logistic regression showed that calf circumference OR= 0. 533 was a protective factor for the development of sarcopenia in lung cancer patients while age ≥ 65 years OR= 3. 789 high SARC-F score OR = 1. 857 and history of smoking OR = 4. 407 were independent risk factors P<0. 05 . Conclusion A high prevalence of sarcopenia is prevalent in lung cancer patients. The risk of sarcopenia was greater for patients ≥ 65 years of age smaller calf circumference higher SARC - F scores and a history of smoking. It is recommended that healthcare professionals should pay more attention to these high - risk groups and implement early interventions to reduce the incidence of sarcopenia in lung cancer patients.