The invention relates to a non-immobilized lipase process in the preparation of reclaiming bio-diesel by a centrifuging technology, which belongs to the field of bio-fuel synthesis. The process comprises the following steps: adding 4 to 9 molars of short chain alcohol ROH based on grease, adding 1 to 20 percent of water based on the grease mass, as well as adding 20 to 200 enzyme activity units of the non-immobilized lipases based on unit oil quality, using lipases of different sources singly or compositely, putting the lipases into any bio-reactor which is suitable for enzyme reaction, controlling the temperature at between 30 DEG C and 65 DEG C, and performing the reaction for 5 to 15 hours so that the yield of the bio-diesel transformed by oil raw materials is over 95 percent; centrifuging the bio-diesel for 5 to 60 minutes under the condition that the speed is 200 to 20, 000 revolution per minute after ending the reaction, wherein more than 95 percent of the lipases are retained on the lower aqueous phase and the middle emulsion layer; and then removing the upper oil phase, and combining the aqueous phase including the lipases and the middle emulsion layer for the next batch of catalytic reaction, thus the loss of the lipases can be effectively reduced to achieve the aim of reusing the lipases repeatedly.