NOVELTY - Diesel oil fraction and aviation fuel fraction are prepared using animal fats and vegetable oils by refining animal and vegetable oils using transformation-complex-absorption process and removing phosphorus, sulfur, nitrogen, metal, and unsaponifiable matter in oil to obtain low impurity content refined oil (3) by filtering raw material oil, removing solid particle impurities, heating to 40-80 degrees C while stirring at 100-1000 rpm, adding 1-3% conversion-complexing agent based on amount of crude oil, stirring for 50-90 minutes at constant temperature, and carrying out centrifugal separation.    USE - Preparation of diesel oil fraction and aviation fuel fraction using animal fats and vegetable oils (claimed).    ADVANTAGE - Preparation method has adjustable process parameters, uses renewable raw materials, avoids all kinds of impurities caused by hydrogenation catalyst poisoning phenomenon, uses device with large operation elasticity, realizes comprehensive utilization of byproduct, solves problem of hydrogen supply difficulty, and reduces operation cost, and prepared diesel oil and aviation fuel are environment-friendly, and have good combustion property and cold flow property and low sulfur and nitrogen content.    DETAILED DESCRIPTION - Diesel oil fraction and aviation fuel fraction are prepared using animal fats and vegetable oils by refining animal and vegetable oils using transformation-complex-absorption process and removing phosphorus, sulfur, nitrogen, metal, and unsaponifiable matter in oil to obtain low impurity content refined oil (3) by filtering raw material oil, removing solid particle impurities, heating to 40-80 degrees C while stirring at 100-1000 rpm, adding 1-3% conversion-complexing agent based on amount of crude oil, stirring for 50-90 minutes at constant temperature, carrying out centrifugal separation when reaction is complete to obtain degummed oil and residue, removing traces of water in oil at 0.07-09 MPa vacuum pressure and 95-105 degrees C temperature for 15-25 minutes, heating dehydrated oil to 90-110 degrees C while stirring, adding 1-4% adsorbent, stirring for 10-30 minutes at constant temperature, and filtering, performing catalytic hydrogenation and deoxidation treatment to refined oil to obtain saturated straight chain alkane and propane by performing hydrogenation and deoxidation treatment stepwise in 2 reactors in series by carrying out carbon-carbon double bond and triple bond hydrogenation saturation at 150-280 degrees C and 0.3-0.4 MPa in the presence of catalyst containing platinum, palladium, nickel, or copper metal as active component, and removing oxygen in oil after hydrogenation at 300-400 degrees C and 2-15 MPa in the presence of catalyst i.e. group VIII metal element and molecular sieve or aluminum oxide and silicon oxide, or processing in 1 reactor at 300-400 degrees C and 2-15 MPa with volume space velocity of 0.5-5 hour-1 and volume ratio hydrogen:oil of 500-1000:1 in the presence of catalyst i.e. group VIII metal element and molecular sieve or aluminum oxide and silicon oxide, performing hydroisomerization and hydrocracking treatment to straight chain alkane at 260-400 degrees C and 2-15 MPa with volume space velocity of 0.5-5 hour-1 and volume ratio hydrogen:oil of 500-1000:1 in the presence of catalyst i.e. group VIII metal element and molecular sieve or aluminum oxide and silicon oxide to obtain high branching degree alkane stream, separating high branching degree alkane stream to obtain liquid hydrocarbons and gaseous hydrocarbons with boiling point in diesel oil, aviation fuel, and naphtha range, directly collecting diesel oil fraction (17) as product or circulating all or portions, continuously performing isomerization and cracking reaction to increase aviation fuel fraction (16), carrying out steam reforming reaction to propane gas hydrocarbon and naphtha mixture, separating and purifying resulting hydrogen, and entering into hydrogen circulation system.    DESCRIPTION OF DRAWING(S) - The drawing shows a flow diagram of preparing diesel oil fraction and aviation fuel fraction using animal fats and vegetable oils.    Animal and vegetable oil stream (1)    Oil refining unit (2)    Refined oil (3)    Aviation fuel fraction (16)    Diesel oil fraction (17)