Objective To investigate the status of social isolation among lung cancer survivors and to analyze its influencing factors. Methods A cross-sectional survey of 228 lung cancer survivors was carried out using the General Alienation Scale, the Self-Esteem Scale, and the Perceived Social Support Scale. Results The lung cancer survivors scored （42.66±7.96） points in social isolation.Social isolation scores were negatively correlated with self-esteem scores, and dimension and total scores of perceived social support （P＜0.01 for all）. Multiple linear regression analysis showed that education level, time after cure, self-esteem, and perceived social support were main influencing factors of social isolation, and could together explain 52.9% of the total variation. Conclusion Lung cancer survivors have moderate or above level social isolation. Medical staff should pay attention to patients with lower education level and shorter time after cure, and take measures to improve their self-esteem and perceived social support, so as to reduce their social isolation.