NOVELTY - An ionic liquid supported molecular sieve catalyst is prepared by conducting chloropropyl functionalization to the molecular sieve, and making triethylamine and conducting ionic liquid synthesis to functionalized molecular sieve in tetrahydrofuran solvent.    USE - Method for preparation of an ionic liquid supported molecular sieve catalyst for biodiesel synthesis (claimed).    ADVANTAGE - The catalyst has high activity and can be used repeatedly, so it is expected to be a clean technical route with great competitiveness.    DETAILED DESCRIPTION - Preparation of an ionic liquid supported molecular sieve catalyst involves    (A) in a reaction kettle, adding lauryl amine, water, and absolute ethyl alcohol at a mol ratio of 1:20- 40:10-15;    (B) adding 30-80 ml mixed solution of 3-chloropropyl triethoxysilane, mixed solution of ethyl orthosilicate and absolute ethyl alcohol at mol ratio of 1:3-5:6-10 into a liquid distributing funnel;    (C) stirring in a water bath at 40-60 degrees C and adding silicon ethyl acetate, ethanol and 3-chloropropyl triethoxysilane at a uniform speed for 4-8 hours;    (D) aging for 15-20 hours in a ventilation kitchen, filtering and drying;    (E) removing template by ethanol extraction, flask, and adding the dried raw powder in 150 ml absolute ethyl alcohol and hydrochloric acid (15 g/100ml/1.5 ml);    (F) placing into an electromagnetic heating sleeve, heating and stirring for 2-3 hours;    (G) washing and filtering, repeating the operation for two to three times;    (H) adding chloropropyl functionalized hexagonal mesoporous silica (CP-HMS) and triethylamine into tetrahydrofuran solvent (30 ml/g) according to 1 g/1.5 mmol, stirring at 40-80 degrees C, and reflowing for 15-25 hours; and    (I) filtering and drying.    An INDEPENDENT CLAIM is included for method using the ionic liquid supported molecular sieve catalyst in synthesis of biodiesel, comprising adding grease and alcohol material alcohol at a mol ratio of 1:5-15 into a reactor, adding ion permeability of at least 1-10% of the total mass of the reactant liquid supported molecular sieve catalyst at 50-200 degrees C and from normal atmosphere to 0.5 MPa, stirring at 60-400 rpm for 1 hour, filtering the mixture of solid catalyst, filtering liquid by standing and layering to obtain biodiesel and crude glycerin, and separating methanol by decompressing and distilling.