The invention provides a collagen-beta-tricalcium phosphate composite particle material with homogeneous particle diameter distribution, and a method and a device for preparing the same. The collagen-beta-tricalcium phosphate composite spherical particle prepared by the method contains a large number of micropores communicated with one another in a particle body, has higher specific surface area,and is advantageous to the flow of tissue fluid for adhering cells; the composite particle has homogeneous particle diameter distribution, and particle materials of the same particle diameter can be obtained without screening treatment; and the spherical particle materials with the same particle diameter can obtain the largest inter-particle porosity after being filled. The particle materials consist of gelatin and beta-tricalcium phosphate, not only has good degradability, but also can provide Ca and P ions for the formation of a new bone when the particle materials are used for bone repair.