The invention relates to a photoelectric detection device, system and method. The photoelectric detection device comprises a silicon photomultiplier, a signal cooperative reading circuit and a signalprocessing unit, wherein the silicon photomultiplier is used for detecting optical pulse signals from a detected sample after the detected sample is irradiated by optical pulse and converting the detected signals into electrical pulse signals; the signal cooperative reading circuit is connected with the silicon photomultiplier and used for cooperatively generating gate control signals for controlling output of the silicon photomultiplier on the basis of pulse control signals which are used for controlling a light emitting device to generate the optical pulse signals, so that the silicon photomultiplier is in a gate control photon counting mode, and the electrical pulse signals output by the silicon photomultiplier are collected in gate control time of the gate control signals; the signal processing unit is connected with the signal cooperative reading circuit and used for counting photoelectron events on the basis of photoelectron number corresponding to each pulse in the collected electrical pulse signals, and when a photoelectron event counting result meets Poisson distribution conditions, the average photoelectron number is calculated on the basis of the counted photoelectron number according to a probability function of Poisson distribution.