The common malignant tumors on the skin mainly include basal cell carcinoma, squamous cell carcinoma and malignant melanoma. Early diagnosis and early treatment of skin malignant tumors is the key. Early diagnosis is better than complete excisional pathological examination, and according to the nature and depth of the tumor, the appropriate excisional scope and whether lymph node biopsy or lymph node dissection are needed. Basal cell carcinoma is the most common malignant tumor of the skin, and the risk factors for its development may be related to sun exposure, age, use of immunosuppressive drugs (AIDS, organ transplant drugs), long-term exposure to carcinogens (UV and ionizing radiation, arsenic, hydrocarbons) and other factors. The treatment of basal cell carcinoma should be different according to the size of the mass, its anatomical location, the type of pathology, and whether it is primary or recurrent. Basal cell carcinoma is less likely to have lymph node metastasis. Primary surgical resection is the most important treatment for basal cell carcinoma. For primary basal cell carcinoma of the face, the extended excision range is 4mm, for well-defined lesions, the extended excision range is 3-5mm, and for aggressive lesions, the extended excision range is 7mm. Squamous cell carcinoma is the second most common type of skin cancer after basal cell carcinoma, and it usually occurs in exposed areas. Common carcinogenic risk factors include sun exposure, carcinogen exposure (pesticides, arsenic, organic hydrocarbons), viral infections (human papilloma virus and herpes simplex virus), immunosuppression (253 times higher risk in kidney transplant patients), heat injury, psoriasis and other possibilities. Lymph nodes must be examined and if abnormalities are found, biopsy of positive lymph nodes for metastases is required. Treatment modalities include conservative treatment and surgery. Conservative treatment 1. Radiation therapy Suitable for patients who are weak and not suitable for surgery Adjuvant treatment for large tumors with high staging 2. Chemotherapy Commonly used as adjuvant treatment for large tumors or recurrent tumors Surgical treatment <2cm, grade I, low risk site, depth to dermis - enlarged 4mm excision >2cm, grade 2,3,4 High-risk site, depth to subcutaneous fat – 6 mm enlargement Lymph node dissection is required for palpable lymph nodes. For clear lymph node metastasis lymph node dissection should be performed. 3.Malignant melanoma Malignant melanoma has a predominant incidence among Caucasians in Europe and the United States, but in recent years we have encountered more and more of them clinically, and some of them come to the hospital for treatment at a relatively late stage, losing the best time for treatment. The common cancer-causing risk factors include: ultraviolet radiation, race, age, family history, trauma to pigmented nevi in various parts of the body, or repeated local friction stimulation, etc. Malignant melanoma staging mainly refers to: Breslow thickness, Clark staging Surgical resection 1. early and extensive resection of the tumor, depending on the stage to determine the extent of abdominal pain resection to avoid postoperative recurrence of recurrence, which affects prognosis and survival time; 2. tumor depth of more than 1mm, prophylactic regional lymph node dissection is advocated, which can prevent distant metastasis; Adjuvant therapy 1. Interferon treatment Beneficial for patients with regional lymph node metastasis or lymph node negative and primary malignant melanoma depth more than 4mm, recommended to do immunotherapy, interferon alpha-2b 5 million units, 2-3 times/ intramuscular or subcutaneous injection. 2.Chemotherapy Dacarbazine, carmustine, cisplatin and tamoxifen can only help to relieve and reduce the tumor load. 3.Radiation therapy is not used as the first choice of treatment for malignant melanoma, but only for unresectable local area to relieve the symptoms of the disease. For malignant tumors of the skin, different treatment modalities are chosen according to the nature, location and stage of different tumors. However, as a rule, early diagnosis and early surgical excision are the most effective ways to treat skin malignant tumors. Plastic surgery has not only mastered good suturing techniques that can take into account the appearance requirements after tumor removal in cosmetic areas, but also can repair skin defects while ensuring the scope of tumor removal. The advantages of plastic surgery in the surgical treatment of cutaneous malignant tumors are obvious.