The study analyzed data from 271 patients with chronic myelomonocytic leukemia (CMML) from five hospitals from 2015–2025, of which 65.68% were male and 34.32% female, with a median age at diagnosis of 26–89 years. According to FAB classification, 40.22% of cases were MD-CMML and 59.78% were MP-CMML, according to WHO 21.77% CMML-0, 24.35% CMML-1 and 53.87% CMML-2. First-line treatment mainly included chemotherapy, 107 patients received only supportive care; in 199 evaluable patients, 97 achieved complete remission, 63 partial remission, 32 stable disease, and 7 progression. By June 30, 2025, 58.67% of patients were alive, 35.79% had died, and 5.54% were lost to follow-up, with a median overall survival of 23.5 months. Multivariate analysis showed that increased neutrophils, monocytes, LDH, β2-microglobulin, decreased hemoglobin and ≥5% blasts in peripheral blood were associated with poor prognosis (p < 0.05). CMML is a heterogeneous disease with poor outcomes, where chemotherapy induces remission but long-term survival is limited.