The invention relates to a method for fixing fluorescent powder by a micro-structure. A micro-structure processing device is used for processing negative photoetching glass cement into a micro-structure body with a placement cavity; the micro-structure body is subjected to cleaning and drying processing; the micro-structure body is placed under a microscope; a probe is used for picking up fluorescent powder, and the fluorescent powder is placed in front of the opening of the placement cavity of the micro-structure body; a macro driving platform is used for driving a heated placement needle; and the placement needle is used for pushing the fluorescent powder to enter the placement cavity of the micro-structure body to realize the fixing of the fluorescent powder in the micro-structure body.The invention also relates to a device for fixing the fluorescent powder by the micro-structure, and comprises a microscope, a micro-structure body, a probe, a placement needle, a placement needle driving mechanism and a heater, wherein the heater is placed on the placement needle driving mechanism to be subjected to heating connection with the placement needle. The device for the fixing fluorescent powder by the micro-structure has the advantages of being simple in operation and low in cost.