1. Topical retinoids: Adapalene (Daphne) ①Applicable type: It is the first-line drug for mild acne alone, and the first-line drug for maintenance treatment in combination with other drugs for moderate acne. ②Mechanism of action: regulates epidermal keratin-forming cell differentiation, improves follicular sebaceous gland duct keratinization, dissolves microcomedema and acne and anti-inflammatory effects, and also has the efficacy of controlling post-inflammatory acne pigmentation and improving acne scar. ③Side effects: Mild skin irritation reactions such as local erythema, flaking, tightness and burning sensation occur, but can gradually disappear with prolonged use. It is recommended to be used in low concentration or in a small range, once a night, and needs to be protected from light. 2. Benzoyl peroxide: Bansai ①Applicable type: When tolerated by patients, it can be used as one of the first choice topical antibacterial drugs for inflammatory acne, either alone or in combination with topical retinoids or topical antibiotics. ②Mechanism of action: It is a peroxide, which slowly releases neo-oxygen and benzoic acid after topical application, and has the effects of killing Propionibacterium acnes, dissolving acne and astringency. ③Side effects: There is also a mild skin irritation reaction, it is recommended that sensitive skin from a low concentration and a small range of trial. 3. Topical antibiotics: Erythromycin, lincomycin, chloramphenicol, fusidic acid ①Type of application: For acne patients with dry and sensitive skin. ②Mechanism of action: Killing Propionibacterium acnes. ③Side effects: May lead to cross-resistance. It is not recommended to be used alone because of drug resistance. It is recommended to be used in combination with benzoyl peroxide or topical retinoids. 4.Selenium disulfide lotion has the effect of inhibiting fungi, parasites and bacteria, and can reduce the free fatty acid content of the skin. Apply the solution slightly diluted evenly on the part of seborrhea, and wash with water after 3-5 minutes. 5, other topical drugs 5% sulfur lotion, etc.