The invention discloses application of apolipoprotein D (ApoD) in the preparation of a Parkinson's 
disease medicament, an ApoD oral preparation and a preparation method thereof. The preparation methodof the ApoD oral preparation comprises the following steps: S1, preparation of an inner-layer 
liposome: mixing 
liposome raw materials, carrying out rotary decompression 
evaporation and blow-
drying, adding ApoD, auxiliary materials and 
ether solution, and carrying out ultrasonic stirring to obtain the 
liposome I; S2, modification of the liposome: adding 
transferrin receptor antibody OX26 subjectedto sulfhydrylation treatment into the liposome I, carrying out 
coupling reaction, connecting the OX26 
antibody to the liposome I so as to obtain liposome II, and carrying out 
chromatography treatment; and S3, combining the outer layer of the liposome II with a 
chitosan layer to obtain composite liposome III. The invention discloses the application of the ApoD in the preparation of the Parkinson'sdisease medicament for the first time, develops the application value of the ApoD in the Parkinson's 
disease medicament field, and provides a brand-new Parkinson's 
disease medicament type-ApoD oral preparation. The preparation has good targeting effect, is not easy to degrade, and has long 
drug effect duration.