Riboflavin can not only promote cell metabolism, but also prevent cardiovascular diseases. People usually need to obtain riboflavin from food or medicine, so the determination of riboflavin is significant for safety and quality control. An ingenious zinc-based metal-organic framework (Zn-MOF) was synthesized which can be used for rapid fluorescence detection of riboflavin with an ultralow detection limit of 2 × 10−8 mol/L. The quenching mechanism is mainly attributed to the fluorescence resonance energy transfer and the absorption competition. In addition, this Zn-MOF can be used as a multifunctional fluorescence probe to specifically recognize acetylacetone and Cr2O72−/CrO42−. Most importantly, it has been applied to the quantitative analysis of milk and energy drinks with satisfactory recovery (100.71%–103.42%). It is the first attempt to use MOF as fluorescence probe to determine riboflavin without additional surface modification and functionalization, which provides a promising functional platform for detecting riboflavin in food industry.