The invention discloses a preparation method of quick-dissolving pericarpium citri reticulatae Pu'er tea powder and the quick-dissolving pericarpium citri reticulatae Pu'er tea powder. The preparation method comprises the steps of pretreating fresh orange peels of pericarpium citri reticulatae and Pu'er raw tea, then carrying out water extraction, and centrifuging, concentrating and freeze drying an extracting solution to obtain the quick-dissolving pericarpium citri reticulatae Pu'er tea powder. The pretreating step comprises the following steps of mixing the cleaned fresh orange peels and the cleaned Pu'er raw tea, soaking in a water solution containing liquorice root, ginger and table salt, and then taking out for carrying out the following operations for at least once: (1) oxidizing at high temperature and humidity, (2) spraying a tannase and cellulase solution, and (3) carrying out enzymolysis treatment at low temperature. According to the preparation method provided by the invention, the raw materials are pretreated, and physical and biological methods are utilized for promoting chemical reaction of active substances in the orange peels, so that Pu'er tea produces a mellow and fresh taste, meanwhile, the loss of active ingredients such as fragrance is reduced, and the prepared quick-dissolving pericarpium citri reticulatae Pu'er tea powder is pleasant in aroma and mellow in taste, and has the characteristics of convenience, quickness, health in drinking and the like.