Abstract: A preparation method of a low-lactose dairy product rich in honey pomelo fiber includes the following steps: washing, cutting and debitterizing peels of honey pomelos to obtain honey pomelo fiber pieces; sterilizing and cooling milk solution, performing the first-round fermentation by inoculating lactic acid bacteria, centrifuging the fermented milk after curding, collecting precipitates, adding water to the precipitates, and performing homogenizing treatment to obtain the first-round fermented milk; mixing the honey pomelo fiber pieces with the first-round fermented milk, and performing the second-round fermentation by inoculating the lactic acid bacteria; or performing the second-round fermentation by inoculating the first-round fermented milk with the lactic acid bacteria, and then mixing the second-round fermented milk with the honey pomelo fiber pieces; and prefreezing the treated honey pomelo fiber pieces treated in the previous step and then performing vacuum freeze-drying to obtain low-lactose dairy p