Disclosed are a compound and a use thereof in the detection of Mycobacterium tuberculosis. The compound is a compound of formula I or a derivative thereof. By using the compound of formula I or the derivative thereof as a detection reagent, and bringing a sample to be tested into contact with the detection reagent, the presence or absence of M. tuberculosis in the sample to be tested can be effectively determined based on whether the sample to be tested undergoes a change in fluorescence after the contact, and results are accurate and reliable. Furthermore, the detection information can be effectively used for diagnosing whether a suspected patient from which the sample to be tested originates has a M. tuberculosis-related disease, thereby achieving the detection of M. tuberculosis-positive patients (active tuberculosis patients) and M. tuberculosis carriers. The compound of formula I is as shown below.