With the more advanced medical level nowadays, many breast cancer patients are recommended to have immunohistochemistry (ER, PR, etc.) and HER2 testing after diagnosis. Currently, most patients and their families do not know why these tests are done and what the significance will be afterwards. Here, we would like to briefly introduce the significance of HER2 test: HER2 is the abbreviation of human epidermal growth factor receptor 2, which plays an important role in regulating cell proliferation, growth and differentiation. The result of HER2 test determines the prognosis of patients, the possibility of tumor recurrence and the length of patients’ survival. There are negative and positive test results. Negative patients have a better prognosis, are less likely to recur and have a relatively longer survival, while positive patients are not so lucky. There is now a consensus in the medical community that treatment of HER2-positive breast cancer patients with biologically targeted drugs can substantially increase patient survival and improve quality of life, and accurate HER2 testing can be of great help in the treatment of breast cancer. Each patient’s disease progression is different, and only early HER2 pathology testing can determine the status and type of breast cancer more comprehensively, so that clinicians can better target and provide effective individualized treatment plans for patients. This has greatly improved the survival and quality of life of patients. Once the HER2 positive status is detected, patients need to take standardized and individualized treatment to avoid being missed or misdiagnosed, select the most appropriate treatment drugs and disease management plan, improve the cure rate and reduce unnecessary medical costs. Knowing the above knowledge, patients with HER2 positive status should not be pessimistic and disappointed because there are many factors that determine the survival rate of breast cancer. As long as patients actively cooperate with the treatment, have regular review, feel comfortable and positive, I believe you will beat the disease.