Low lung function is one of the causes of most lung diseases and can bring about many unpredictable complications, usually related to lung disease, with very serious effects. Among the life elements of air, water and food, we can choose safe food and water, while the air we inhale into our lungs is not chosen by us, so in many consciousness, it seems that there is nothing to do to nourish our lungs. However, the lungs are the organ of direct contact between the body and the outside world, and if no attention is paid to nourishing them, then they are made vulnerable to damage and pulmonary diffusion dysfunction ensues. The amount of diffusion depends on the difference in partial pressure of gas on both sides of the membrane, diffusion area, distance, time, molecular weight of gas and its solubility in the diffusion medium. Decreased diffusion function can be caused by emphysema and other lung tissue lesions, diffuse interstitial lung fibrosis, and other diseases. To prevent pulmonary diffusion dysfunction, we need to do the following: 1, pay attention to avoid cold and warmth, prevent cold and flu. 2. Avoid contact with foreign bodies of definite etiology. 3, pay attention to diet and nutrition. 4.Ginseng, mealybug, Chuanbei powder, safflower, cordyceps in appropriate amounts, powder human capsules, moderate amount of consumption, or daily consumption of walnuts 2-3. The body can be seen with reduced thoracic respiratory movement, and fine wet rales or twisted sounds can be heard in both lungs. There are varying degrees of cyanosis and pestle-like fingers. Signs of right heart failure may appear in late stages.