Objective To explore the effects of medical customized diet HDMTM on nutritional status fatigue and quality of life in patients with metastatic lung cancer. Method A prospective selection of 108 patients with metastatic lung cancer admitted to Wuhan Third Hospital between June 2021 and June 2023 was conducted. They were randomly divided into two groups using a random number table method. The control group 54 cases received routine nutritional support while the intervention group 54 cases received HDMTM support. After intervention the nutritional status of the two groups serum albumin ALB total protein TP hemoglobin Hb lung function forced expiratory volume in one second FEV1 forced vital capacity FVC maximum ventilation volume per minute MVV cancer - related fatigue score and lung cancer specific quality of life assessment FACT - L score were compared. Result After 14 days of intervention the nutritional status and lung function of the two groups of patients improved compared to before treatment. The cancer-related fatigue score decreased and the FACT-L score increased with statistical significance P<0. 05 . After 14 days of intervention the improvement of FEV1 92. 84 ± 4. 52 % MVV 91. 29 ± 5. 45 L/ min FVC 3. 55 ± 0. 39 L Hb 111. 12 ± 6. 57 g / L ALB 43. 11 ± 4. 58 g / L and TP 69. 78 ± 3. 16 g / L in the intervention group was better than that in the control group with statistical significance P<0. 05 . The scores of emotional fatigue 4. 85 ± 1. 22 behavioral fatigue 3. 13 ± 1. 52 physical fatigue 3. 38 ± 1. 19 and cognitive fatigue 3. 15 ± 1. 14 after 14 days of intervention were lower than those of the control group with statistical significance P< 0. 05 . The FACT-L score 82. 85 ± 5. 25 and FACT-L score 93. 35 ± 4. 25 after 7 days of intervention were higher than those of the control group with statistical significance P< 0.05. Conclusion HDMTM is more targeted and scientific. Compared to conventional nutritional support it has a more significant effect in patients with metastatic lung cancer. It can not only improve lung function and nutritional status promote disease recovery but also alleviate fatigue improve quality of life and have higher utilization value.