To probe the effect of whole-process nutrition management on the nutritional status of patients with esophageal cancer undergoing radiotherapy, 100 patients were allocated to the control group (n = 50) and observation group (n = 50). Patients in both groups underwent routine treatment after admission. The control group adopted conventional nutrition management, while the observation group was given whole-process nutrition management. Compared to the control group, the patient-generated subjective global assessment score in the observation group declined after intervention (P < 0.05). Levels of prealbumin, albumin, transferrin, immunoglobulin A, immunoglobulin G, immunoglobulin M, CD3+, and CD4+ in the observation group were elevated compared to the control group after intervention (P < 0.05). According to the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire-Core 30, the observation group exhibited higher scores in the aspects of family understanding and cooperation, mental condition, appetite, daily life, and sleep quality than the control group after intervention (P < 0.05). Furthermore, the incidence of adverse reactions in the observation group was lessened compared to the control group (P < 0.05). Hence, implementing whole-process nutrition management in patients undergoing radiotherapy can promote their nutritional status and quality of life.