Malignant pleomorphic undifferentiated sarcoma of the thigh is a more serious tumor, but the cells of the sarcoma are not differentiated and differ from normal cells in morphology. Malignant pleomorphic undifferentiated sarcoma of thigh is a malignant tumor, which is mainly related to the living environment, body immunity and bad dietary habits. The appearance of malignant pleomorphic undifferentiated sarcoma of thigh may be due to the exposure to radiation in the living or working environment, and the low resistance of oneself, which produces the cancer cells, and is prone to lesions, spreading to the surrounding tissues, which will seriously affect the normal life, and even endanger the life. Malignant pleomorphic undifferentiated sarcoma of the thigh should be consulted in time, keep a good mood, eat a light diet and avoid spicy and stimulating food.