A method for preparing a low-lactose dairy product rich in honey pomelo fibers, the method comprising: cleaning, dicing and debitterizing peel fibers of honey pomelo to obtain honey pomelo fiber blocks; sterilizing and cooling liquid milk, inoculating same with lactic acid bacteria for primary fermentation until the content of lactose is no longer reduced, performing centrifuging after milk is solidified, collecting a precipitate, adding water to the precipitate until the pH value is greater than 5.0, and performing homogenization treatment to obtain primary fermented milk; mixing the honey pomelo fiber blocks with the primary fermented milk, and inoculating same with lactic acid bacteria for secondary fermentation until the content of lactose is lower than 0.04%; or inoculating the primary fermented milk with lactic acid bacteria for secondary fermentation until the content of lactose is lower than 0.04%, and then mixing same with the honey pomelo fiber blocks; and pre-freezing the honey pomelo fiber blocks treated by means of the above-mentioned steps, and performing vacuum freeze drying to obtain the low-lactose dairy product rich in honey pomelo fibers.