Objective To investigate the effectiveness of psychological interventions in improving negative emotions, pain, and sleep quality among patients with advanced colon cancer. Methods From March 2021 to March 2023, a total of 218 patients with advanced colon cancer were selected from the First Affiliated Hospital of Soochow University based on strict inclusion and exclusion criteria. Patients were randomly assigned to either the control group or the observation group (109 patients each) using a random number table. The control group received standard medical care, while the observation group received psychological interventions. Both groups were assessed for anxiety and depression levels [using the Self-Rating Anxiety Scale (SAS) and the Self-Rating Depression Scale (SDS)], sleep quality [measured by the Pittsburgh Sleep Quality Index (PSQI)], pain intensity [using the Visual Analog Scale (VAS)], and overall quality of life. Inter-group comparisons were conducted. Results Post-intervention assessments showed a decrease in SAS and SDS scores for both groups, with the observation group demonstrating a more significant reduction (P < 0.05). Additionally, the observation group reported significantly lower pain levels (VAS scores) and improved sleep quality (PSQI scores) compared to the control group, along with a markedly higher quality of life as measured by the Quality of Life Core Questionnaire (QLQ-30) (P < 0.05). Conclusion This study demonstrates that psychological interventions effectively alleviate anxiety, depression, pain, and sleep disturbances in patients with advanced colon cancer, thereby improving their overall quality of life. However, further studies are required to explore the long-term impact on prognosis.