Near-infrared long-afterglow florescent powder and preparation method thereof

The invention discloses a near-infrared long-afterglow florescent powder. A substrate material of the near-infrared long-afterglow florescent powder is ZnZA1YSiXO(Z+1.5Y+2X) or ZnZA1YGeXO (Z+1.5y+2X) or ZnZGaYSiXO(Z+1.5Y+2X), wherein X is more than or equal to 1 and less than or equal to 5, Y is more than or equal to 1 and less than or equal to 5, and Z is more than or equal to 1 and less than or equal to 5; and the substrate material is doped with 0.001-5mol% of Cr and 0.001-20mol% of M, wherein M is one or two of an alkali metal element, an alkaline-earth metal element and a rare-earth element. The invention further discloses a preparation method of the near-infrared long-afterglow florescent powder. The near-infrared long-afterglow florescent powder prepared by using the method can be excited under visible light; in addition, the afterglow time of the near-infrared long-afterglow florescent powder is longer than 120h; and furthermore, the near-infrared long-afterglow florescent powder has an optical-excitation luminescence property and can be well used for bioimaging.