The invention provides a
polymer microsphere with a controllable particle size and a method for preparing the
polymer microsphere. The method comprises the following steps of: (1) preparing a water phase containing an emulsifier, wherein 0.01-0.15 part by weight of emulsifier is added to every 100 parts by weight of water, and preparing an
oil phase containing a
monomer and an initiator, wherein 0.5-5 parts by weigh of initiator and 20.0-50.0 parts by weight of
monomer are added to every 100 parts by weight of oil; (2) increasing pressure on one side of a membrane by adopting the
membrane emulsification method, pressing the mixture of the water phase and the
oil phase into the membrane to obtain an uniform
emulsion, wherein the volume ratio of the water phase to the
oil phase is (1:3) to (1:5); and (3) enabling the
emulsion obtained in the step (2) to be subjected to
polymerization reaction for 10-24 hours to obtain the
polymer microsphere. The technical scheme solves the problems that the original mixing method is complex in process flow, has a high requirement for raw materials, equipment and
process conditions and consumes a large amount of energy. According to the technical scheme, the method comprises the steps of: dissolving a dye into the oil phase, mixing the oil phase with the water phase, emulsifying under a certain pressure by using a
membrane emulsification device, and enabling the
emulsion to be subjected to
polymerization reaction to obtain the
colored microsphere.