Survival after lung metastasis from breast cancer cannot be generalized, but is mainly related to the number, size and specific location of metastases and the patient’s subsequent treatment. Generally speaking, when breast cancer metastases to the lung, it indicates that the patient’s condition has entered the middle and late stage. If the number of metastases is single and small, and the metastatic site is at the edge of the lung, the patient’s survival can be prolonged after active and effective treatment, and even a few patients can live with the tumor for several years to more than 10 years. If there are more metastases, or if the metastases are large, resulting in severe symptoms such as fever, chest tightness, wheezing, sputum and blood, the prognosis of such patients is generally poor, and survival time is often less than 1 year. However, the specific survival period is difficult to judge and varies from person to person. In conclusion, when lung metastasis occurs in breast cancer, early and aggressive treatment is still the key to improve patients’ prognosis, enhance the quality of survival and prolong the survival period.