The invention discloses a 3D printing equipment leveling system and an automatic leveling method thereof, belonging to the field of research and development of powder additive manufacturing equipment. The system includes: working chamber, including working platform, working chamber roof, working chamber left vertical board, working chamber right vertical board, working chamber front vertical board, working chamber rear vertical board; powder spreading device, including knife rest, posture adjustment Unit, drive guide rail, reducer, adapter shaft, drive motor; forming part lifting device, including cylinder block, base plate, universal adjustment bearing, jacking support plate, leveling unit and lifting unit; and image acquisition device and data processing device. The invention can automatically perform leveling, saves a lot of time, ensures leveling accuracy, can eliminate subtle errors caused by scraper jamming, substrate processing, manual loading and unloading of substrates, etc., and is more efficient and smarter.