The invention discloses a fastening structure of a pressure cooker, which consists of a pot cover (1) and a pot body, wherein the pot body comprises a middle base or shell (3) and an internal pot (5) arranged in the middle base or shell; a sealing ring (2) is arranged between the internal pot and the pot cover; and the pot cover and the pot body are spirally fastened or separated. The fastening structure is characterized in that: more than two clamps (4) are fixed on the edge of the middle base or shell (3) along the circumference; each clamp has more than one L-shaped fastening part; and thepot cover (1) is provided with a pot cover fastener (1-1) matched with the fastening part of each clamp. In the invention, the manufacturing processes of the pot cover and the lamps are simple, requirements on size precision are low, and cost is relatively low; the spot cover has no obvious gaps, so that a user is prevented from injury during washing; assemblage and use are simple; both the innerpart of the pot cover and the clamps are convenient to wash; and the mouth part of the internal pot is not a clamping face, so that the cover is relatively easy to open and close.