The invention relates to a preparation method for epoxypropane. The preparation method comprises the following steps: with toluene as a solvent, adding a titanium silicate molecular sieve with a contact angle of 10 to 20 DEG C into a reactor, carrying out stirring, then adding a toluene solution containing a silylating reagent into a flask drop by drop and carrying out stirring for a reaction; carrying out centrifugation after completion of the reaction, washing off toluene on the surface of the molecular sieve by using acetone, then putting the molecular sieve into a baking oven so as to allow acetone on the surface of the molecular sieve to volatilize, taking the molecular sieve out and naturally cooling the molecular sieve to room temperature so as to obtain a modified titanium silicate molecular sieve, wherein the contact angle of the modified titanium silicate molecular sieve is 80 to 100 DEG C; and putting hydrogen peroxide and the modified titanium silicate molecular sieve into a reactor, introducing propylene into the reactor, carrying out pressurization so as to liquefy propylene and carrying out a reaction under stirring. According to the invention, a water phase and an oil phase are mixed to form stable Pickering emulsion, so the contact area of the water phase and the oil phase is increased, and a mass transfer rate is improved; no solvent is used for homogenizing a reaction system; and the product, i.e., epoxypropane, is easy to separate.