Background: Therefore, the development of reliable analytical techniques with high selectivity and sensitivity to detect hydrazine is required for the protection of human health and safety. Objectives: Traditional methods for detecting N2H4 are frequently time-consuming, less accurate, and unsuitable for the analysis of living systems. Numerous fluorescent probes for hydrazine have been produced and gained some valuable results recently. The creation of a simple fluorescent probe for hydrazine detection is the goal of this project Method: In this study, 300 µL of probe 3-methyl-2-oxo-2H-chromen-7-yl propionate (MOCP) was mixed with an equivalent amount of the solution of each analyte to obtain the measurement solution. Following a 10-minute room temperature incubation period, the fluorescence spectra of the resultant solution were recorded. Results: The fluorescence intensity of the probe was noticeably enhanced when N2H4 was added to the probe, but almost no fluorescence enhancement was observed when other competitive ions were added. Conclusion: A hydrazine fluorescent probe based on 4-hydroxycoumarin fluorophore was developed. The probe MOCP displayed high sensitivity and selectivity for hydrazine, with a color change from colourless to blue for detection by the naked eye. Moreover, it demonstrated a low detection limit of 20 nM and a fast reaction time of 30 s.