Objective To investigate the sleep quality of patients with advanced cancer and its related influencing factors. Methods The self⁃made scale was used to investigate the general situation, nutritional status, exercise status and treatment of the patients. The Pittsburgh sleep quality index（PSQI）was used to investigate the sleep quality of the patients. The total score of sleep quality and the scores of each item were evaluated by t test. The abnormal incidence rate of sleep quality was analyzed by rank sum test. The multiple factors analysis of sleep quality was analyzed by ordinal Logistic regression and correlation analysis.. Cronbach α coefficient was used to estimate the internal consistency, and Spearman Brown formula was used to estimate the reliability. Results The scores of seven sleep quality components and the total score of PSQI of patients with advanced cancer were significantly higher than those of the normal sleep quality of healthy people in China (P<0.001). The internal consistency of PSQI scale applied to hospitalized patients with advanced cancer was high, with Cronbach α coefficient of 0.854. 61% of patients with advanced cancer had abnormal sleep quality. The incidence of sleep disorders in patients with decreased body mass index (BMI) (P=0.010), severe cancer pain (P<0.001), PS score 3 group (P<0.001), only symptomatic treatment (P<0.001), low fitness frequency (P<0.001) and less than 30 minutes of daily fitness (P=0.010) was significantly higher than that in other patients. Logistic regression analysis showed that pain (P<0.001) was a significant risk factor for abnormal sleep quality. Conclusions The incidence of abnormal sleep quality in hospitalized patients with advanced cancer is high, but the sleep quality is poor. The factors that affect the sleep quality of patients with advanced cancer are mainly related to the patient′s condition. According to these characteristics, individualized programs should be developed to improve the sleep quality of patients with advanced cancer, so as to improve the quality of life of patients with advanced cancer.