The invention discloses a diagnosis and treatment integrated gradient osteochondral bionic scaffold and a preparation method thereof, which adopts a DLP photocuring 3D printing technology, and the preparation method comprises the following steps: respectively preparing sol of a cartilage layer, a cartilage calcification layer and a subchondral bone layer, and preparing cartilage layer sol by utilizing quercetin, methacrylate esterified gelatin and an LAP solution; preparing cartilage calcification layer sol by utilizing quercetin, methacrylate esterified gelatin, iron-doped hydroxyapatite andan LAP solution; preparing subchondral bone layer sol by utilizing quercetin, methacrylate esterified gelatin, iron-doped hydroxyapatite and an LAP solution. The scaffold prepared by the method has structural gradient and material gradient, has good mechanical properties and biocompatibility, and has good bone induction capability and bone conduction capability, which can induce regeneration of bone tissue defect parts. The gradient scaffold provided by the invention has an MRI diagnosis function, which can be used to accurately evaluate the real-time condition of osteochondral defect repair in vivo.