The invention belongs to the technical field of display, and particularly relates to photodiffusion powder, a preparation method of the photodiffusion powder, quantum dot photoresist and a quantum dot color film.The preparation method of the photodiffusion powder comprises the steps that alkoxy silane is subjected to a cohydrolysis condensation reaction under the acidic condition or the alkaline condition, and the photodiffusion powder is obtained.The quantum dot photoresist made of the photodiffusion powder and the quantum dot color film are further disclosed.The photodiffusion powder has an organic chain segment structure and an inorganic structure, and is good in compatibility with all kinds of components in a quantum dot photoresist system, a good dispersion effect is achieved, and the uniformity of the photoresist is increased.The quantum dot color film made of the quantum dot photoresist is even in film quality and high in light utilization rate.