Backgrounds Hand grip strength (HGS) is one of diagnose criteria factors of sarcopenia and is associated with the survival of patients with cancer. However, few studies have addressed the association of HGS and 1 year mortality of patients with cancer cachexia. Methods This cohort study included 8466 patients with malignant solid tumour from 40 clinical centres throughout China. Cachexia was diagnosed using the 2011 International cancer cachexia consensus. The hazard ratio (HR) of all cancer cachexia mortality was calculated using Cox proportional hazard regression models. Kaplan-Meier curves were generated to evaluate the association between HGS and the 1 year mortality of patients with cancer cachexia. The interaction analysis was used to explore the combined effect of low HGS and other factors on the overall survival of patients with cancer cachexia. Results Among all participants, 1434 (16.9%) patients with cancer were diagnosed with cachexia according to the 2011 International cancer cachexia consensus with a mean (SD) age of 57.75 (12.97) years, among which there were 871 (60.7%) male patients. The HGS optimal cut-off points of male and female patients were 19.87 and 14.3 kg, respectively. Patients with cancer cachexia had lower HGS than those patients without cachexia (P < 0.05). In the multivariable Cox analysis, low HGS was an independent risk factor of cachexia [HR: 1.491, 95% confidence interval (CI): 1.257-1.769] after adjusting other factors. In addition, all of cancer cachexia patients with lower HGS had unfavourable 1 year survival (P < 0.001). In a subset analysis, low HGS was an independent prognosis factor of male patients with cancer cachexia (HR: 1.623, 95% CI: 1.308-2.014, P < 0.001), but not in female patients (HR: 1.947, 95% CI: 0.956-3.963, P = 0.0662), and low HGS was associated with poor 1 year survival of digestive system, respiratory system, and other cancer cachexia patients (all P < 0.05). Low HGS has combined effects with high neutrophil-to-lymphocyte ratio or low albumin on unfavourable overall survival of patients with cancer cachexia. Conclusions Low HGS was associated with poor 1 year survival of patients with cancer cachexia.