A formation platform for a three-dimensional printing device is provided. The formation platform includes a base (100), one or more positioning assemblies (200), a substrate (300), and one or more calibration assemblies (400). The positioning assembly (200) includes a damper (210) and a resilient element (220), the damper (210) is movably disposed at the base (100), and the resilient element (220) is associated with the clamper (210) to push the clamper (210) toward the base (100). The substrate (300) is disposed on the base (100), and a portion of an edge of the substrate (300) is compressed by the damper (210) to fix the substrate on the base (100). The calibration assembly (400) includes a screw rod (410); the screw rod (410) is disposed on the base (100) and in contact with the substrate (300). By the positioning assembly (200) collaborating with the calibration assembly (400), horizontal adjustment of the substrate (300) can be made, and the substrate (300) can be easily installed or removed.