According to the nature and severity of acne lesions, acne can be classified into 3 or 4 grades: Grade 1 (mild): acne only; Grade 2 (moderate): inflammatory papules in addition to acne; Grade 3 (moderate): pustules in addition to acne and inflammatory papules; Grade 4 (severe): nodules, cysts or scarring in addition to acne, inflammatory papules and pustules. The grading of acne reflects the severity of acne and the nature of the lesions, so the treatment of acne should be based on the grading and the selection of appropriate drugs and treatments. The treatment plan for acne is not set in stone, but should be flexible according to the actual situation of the patient, fully reflecting the principle of individualized treatment. Grade 1: Topical treatment is generally used. If only acne is present, topical retinoids are the best choice. Medical skin care products that exfoliate, dissolve acne, inhibit sebum production, and are antibacterial can also be used as adjunctive treatments. Grade 2: Usually treated as Grade 1 acne, but oral antibiotics may be used for those with more inflammatory papules and pustules that do not respond well to topical treatment. Combination therapy, such as oral antibiotics combined with topical retinoids, or physical therapy such as blue light, photodynamic therapy, or fruit acid therapy, may also be used for this type of acne. Grade 3: Patients in this category often require a combination of treatments, with systemic antibiotics as one of the basic treatments and a sufficient course of treatment. The most commonly used combination therapy is oral antibiotics combined with topical retinoids or topical benzoyl peroxide. Hormonal therapy has also been used with good results in women requiring contraception or with other gynecologic indications. Other combination therapies described in this guideline can also be used, such as red and blue light and photodynamic therapy, but attention should be paid to the interactions and contraindications between tetracyclines and isotretinoin, as well as to the development of photosensitivity. For poor results, oral isotretinoin alone can be used, as well as topical peroxymethylphenidate. For those who need to use antibiotics systematically for more than 3 months, the combination of peroxymethol, an antibacterial agent that does not cause bacterial resistance, is necessary to prevent and reduce the development of drug resistance. Grade 4: Oral isotretinoin is the most effective treatment for this group of patients and can be used as first-line therapy. For patients with more inflammatory papules and pustules, a combination of systemic antibiotics and peroxynivalenol may be used before switching to oral isotretinoin for lesions such as cysts and nodules. Combination therapy as described above for grade 3 acne and as described in this guideline may also be tried. Regardless of the level of acne, it is important to maintain treatment once symptoms have improved.