Abstract: Objective To investigate the effectiveness of load deep breathing training combined with pulmonary rehabilitation in the recovery of lung cancer patients after immunotherapy.Methods A retrospective analysis was conducted on 115 lung cancer patients who received immunotherapy at Changzhi People's Hospital between January 2021 and August 2024. The patients were divided into two groups: a conventional training group (n=50, receiving standard pulmonary rehabilitation) and a combined training group (n=65, receiving load deep breathing training combined with pulmonary rehabilitation). The two groups were compared in terms of respiratory function (assessed by the mMRC questionnaire), pulmonary function forced vital capacity (FVC), forced expiratory volume in 1 second (FEV1), and FEV1/FVC, cardiopulmonary exercise indicators maximum oxygen uptake (VO₂max), anaerobic threshold (AT), and peak ventilation (VE), quality of life (assessed by the FACT-L scale), psychological status (assessed by the SAS scale), and stress level (assessed by the PSS-14 scale).Results After treatment, the mMRC score in the combined training group was significantly lower than in the conventional training group (t=6.125, P<0.05); FVC, FEV1, and FEV1/FVC values were significantly higher than those in the conventional training group (t=2.740,t=4.263,t=2.411, P<0.05); VO₂max, AT, and VE indicators were also markedly superior in the combined training group (t=4.652,t=3.327,t=3.047, P<0.05). The FACT-L scores in all dimensions were higher, while SAS and PSS-14 scores were lower in the combined training group than those in the conventional training group (P<0.05). The total incidence of adverse reactions was lower in the combined training group, though the difference was not statistically significant (χ²=4.830, P<0.05).Conclusions Load deep breathing training combined with pulmonary rehabilitation can significantly improve respiratory and lung function in lung cancer patients after immunotherapy, enhance cardiopulmonary exercise capacity, relieve psychological stress, reduce adverse reactions, and markedly improve quality of life.