The invention relates to a preparation method of a platelet-rich fibrin film (PRF) and belongs to the technical field of a biological material and tissue engineering. The PRF provided by the invention is prepared by the following steps: adopting a venous blood sample; carrying out centrifugal operation by a centrifuge at the speed of 1000rpm to 3000rpm for 10 to 30 minutes; cutting off a red blood cell layer of a centrifugal product at a part, far away from a crossed part by 1mm to 3mm, on a red blood cell at the crossed part of the PRF and the red blood cell; pouring off supernatant and putting obtained PRF gel on a plurality of layers of gauze and covering by a plurality of layers of gauze; forcedly and continuously extruding the gauze to slowly press the PRF in the gauze and continuously dehydrate. The PRF provided by the invention has a dense three-dimensional structure and is completely dehydrated; growth factors are slowly and lastingly released; in soft and hard tissue regeneration, the PRF is an ideal growth factor source; when the PRF is planted into a body within 4 weeks, the growth factors are slowly released and a self film-shaped structure also keeps relatively stable; the PRF can also be used as a barrier film of a GBR (Guided Bone Regeneration) region and is used for continuously separating a sealed bone generation space for the GBR region.