The invention discloses a Cherenkov event pulse digitization method and device, and belongs to the fields of event pulse detection systems, photoelectric signal processing and nuclear detection. The method comprises the following steps: S1, obtaining a data set of the of the Cherenkov event emission photons; S2, obtaining a data set of background light, S3, calculating a joint likelihood probability function or a posterior probability function of the data set of the Cherenkov event emission photons in each time period; S4, judging whether the data set of the background light in each time period is the data set of the background light or the data set of the Cherenkov event emission photons. The device comprises a Cherenkov event emission photon data set obtaining module, a background photondata set obtaining module, an independent photon correlator module and an event classifier module. The method and device are high in signal-to-noise ratio and spatial resolution.