The present invention provides a method for preparing large particles of titanium-silicalite molecular sieves. The method of the present invention includes the steps of preparing a dispersion solution of a primary crystalline molecular sieve; forming an aggregated particle solution by adding a flocculating agent and a coagulating agent into the dispersion solution; mixing the aggregated particle solution with a synthesis gel to form a mixture; and heat-treating the mixture. The average diameter of the titanium-silicalite molecular sieves in the present invention is more than 5 μm. In the preparation of cyclohexanone oxime using the molecular sieve of the present invention as the catalyst, the selectivity and conversion rate of cyclohexanone oxime are high, the usage of hydrogen peroxide is enhanced, and the catalyst is easy to be recovered.