This research leverages the fluorescence properties of a europium metal–organic framework (EuMOF) to assess the presence of aldehydes in food. The EuMOF demonstrates three distinct excitation peaks, with an unusual change in fluorescence intensity attributed to the excessive aggregation observed in the initial two peaks. Aldehydes, specifically monoaldehyde compounds (MACs) and dialdehyde compounds (DACs), can engage with the amine groups on the surface of the EuMOF through a Schiff reaction. This interaction disrupts the accumulation process during dilution and allows for the quantification and differentiation of aldehyde compounds based on their unique fluorescence behaviors. By conducting a series of sample dilutions, the ratio between the first two fluorescence excitation peaks can be determined, leading to the creation of a data matrix. The quantitative evaluation of aldehyde‐derived compounds is enabled by deconstructing the original sample matrix using reference matrices of EuMOF and a reaction mixture containing the aldehyde standard. This innovative technique for monitoring aldehydes eliminates the need for sample pretreatment, aldehyde derivatization, and the use of hazardous chemicals in the detection process, offering significant economic and public health benefits.