Objective To analyze the clinical features of paraneoplastic neurological syndrome（PNS）to improve the early diagnosis and treatment of this disease. Methods The clinical manifestations,laboratory results and treatment effects of 21 patients with PNS admitted to Huizhou First People's Hospital and Huizhou Central People's Hospital from October 2019 to October 2022 were retrospectively analyzed,and literature review was performed. Results There were 10 paraneoplastic syndromes in 21 patients,of which classical syndrome accounted for 28.6%（6/21）,the most common was limbic lobe encephalitis．Anti-neuronal antibodies were detected in blood or cerebrospinal fluid in 20 cases,with the highest positive rate of non-characteristic antibodies（12/20）,among which the positive rate of TBA detection by semi-quantitative brain tissue sections was the highest（7/20）;Eight cases with characteristic antibodies had the highest positive rate of anti-Yo antibody（6/8）．All 21 patients have been followed up so far,and 8 cases have found primary tumors,4 of which were after neurological lesions．There was 69.25%（9/13）of patients responded to hormone therapy or（and）gamma globulin therapy. Conclusions Non-classical syndrome accounts for more patients with PNS,and both classical and non-classical paraneoplastic syndromes should be screened for tumors,and those who have not found tumors should be closely followed．The positive rate of non-characteristic antibodies is the highest,indicating that there may still be many related antibodies in PNS that are not clear,and the positive of non-characteristic antibodies should also be paid attention to in clinical work．