A medical cornea patch and its preparing method are disclosed, which implants autogenous mesenchyma stem cell to amnion for being carrier to treat cornea disease. The process includes: obtaining bone marrow 10ml from healthy person in clinical practice, diluting by PBS in ratio of 1:1, adding 5ml of Ficoll, centrifuging for 20 minutes, sucking out the nebulous single nuclei cell suspension, washing three times by PBS, implanting to 10% FBS containing culture medium of a-MEM, fetching 2í‡105 cell of the fourth generation to treated amnion with size of 1.5cmí‡1.5cm after 10 to 14 days, adding to culture medium to continue culturing, till the cell grow fully of the whole amnion.