Hypofractionated gastric cancer is usually a malignant tumor with a high degree of malignancy, but it is not the most malignant tumor; undifferentiated gastric cancer is more malignant. In clinical practice, tumors are usually classified into highly differentiated, moderately differentiated, poorly differentiated and undifferentiated cancers. Under normal circumstances, the lower the differentiation, the higher the malignancy of the cancer, the worse the treatment effect, the worse the prognosis, and easy to recur. Undifferentiated cancer has high tumor activity and may have metastasis at an early stage, so its malignant degree is even higher. After diagnosed with stomach cancer, patients should set their mind right, follow the principle of early detection and early treatment, and actively carry out treatment no matter what type of stomach cancer they are diagnosed with. It is suggested that stomach cancer patients should consult doctors in time when they feel unwell to avoid aggravation of their condition.