A three-dimensional (3D) printing apparatus includes a tank containing a forming material in liquid, a platform dipped into or moved away the forming material, a curing device disposed besides the tank or the platform, and a control device electrically connected to at least one of the tank and the platform and the curing device. An inner bottom of the tank includes a forming area and a peeling area in a stepped shape, and the forming area is higher than the peeling area. A 3D printing method includes providing the 3D printing apparatus, then the liquid-state forming material between the platform and the forming area is cured to form a solidification layer. Afterwards, a position and an occupied proportion of the solidification layer corresponding to the inner bottom, and a movement range of a relative movement is determined according thereto so as to completely peel off the solidification layer.