Breast cancer in pregnancy usually manifests as breast lumps, bloody nipple discharge, redness and swelling of breasts, and enlarged axillary lymph nodes during pregnancy, etc. Patients should seek early medical consultation and evaluation to avoid delay. Typical manifestation of breast cancer during pregnancy is painless lump in the breast, and the patient’s breast can be touched with a lump or thickened area of the breast. However, due to some physiological changes of the breast during pregnancy and breastfeeding, such as breast engorgement, enlargement, nipple overflow, etc., breast tumors are easy to be covered up, and their symptoms and signs are often ignored. If suspicious breast lumps are found during pregnancy, patients should consult the doctor as soon as possible, and breast ultrasonography should be performed for diagnostic evaluation. Hollow needle aspiration biopsy under local anesthesia is also a safer diagnostic method, and for patients who are clearly diagnosed with gestational breast cancer, surgical excision of the tumor is feasible, together with the adjuvant chemotherapy, postpartum adjuvant chemotherapy, endocrine therapy and other therapeutic options. It is suggested that patients should consult the doctor in time for early detection and treatment, and should not be negligent so as not to cause delay in their condition.