Squamous cell carcinoma is a relatively common type of skin malignancy. Squamous cell carcinoma can be classified into highly differentiated, moderately differentiated and poorly differentiated according to the degree of cellular variation. Surgery is the first choice for moderately differentiated squamous cell carcinoma. The best surgical method is Mohs microsurgery, which is performed by expanding the excision on one side and performing frozen section on the other side to ensure that there are no cancer cells left at the edge and the base, then repairing and suturing the skin, and then allowing the patient to review regularly. If the squamous cell carcinoma is too large or invasive or the patient is too old and cannot tolerate surgery, other conservative treatments such as cryotherapy or radiotherapy can be chosen.