The present invention discloses a method for preparing a perovskite quantum dot fluorescent ring from methylammonium lead bromide perovskite quantum dots. The method comprises: 1, washing a glass slide, wherein a piranha solution (comprising concentrated sulfuric acid and 30% hydrogen peroxide according to a ratio of 7:3) is poured, boiling is performed, an ethanol solution and a deionized water solution are sequentially poured, ultrasonic cleaning is respectively performed for 15-30 min, the glass slide is taken out, and blow drying is performed with nitrogen; 2, dissolving the dimethylformamide (DMF) solution of methylammonium lead bromide perovskite quantum dots in toluene to prepare a methylammonium lead bromide perovskite quantum dot toluene solution; and 3, dropping the methylammonium lead bromide perovskite quantum dot toluene solution on the glass slide by using a pipette, and waiting at a room temperature until the methylammonium lead bromide perovskite quantum dot toluene solution is dried so as to obtain the perovskite quantum dot fluorescent ring. According to the present invention, the perovskite quantum dot fluorescent ring is prepared based on the methylammonium lead bromide perovskite quantum dots, such that the self-assembly of the methylammonium lead bromide perovskite quantum dots is achieved, and the methylammonium lead bromide perovskite quantum dot fluorescent ring preparation method is firstly provided.