Capsaicin with high purity has anti-inflammatory, bacteriostatic, analgesic and insecticidal effects, and is widely used in the pharmaceutical industry. Capsaicin was extracted from capsicum by hot dipping method, and the content of which was determined by high performance liquid chromatography. The extraction process was optimized by single factor test and orthogonal experiment. The results showed that the optimum extraction conditions were blanching temperature 60 ℃, extraction temperature 40 ℃, extraction time 3 h and chopping degree 0.5 cm (edge length). Under the condition the extraction rate of capsaicin could reach to 0.27%. Compared with the traditional ethanol reflux method, ultrasound-assisted organic solvent method and other methods of capsaicin extraction, such as decompression internal boiling method, the extraction rate of capsaicin had been significantly improved.