The invention relates to a LaBr3(Ce) crystal-based multi-channel gamma energy spectrum logging instrument. The instrument comprises a probe part, an operating platform, a cable and a winch, wherein the probe part comprises a LaBr3(Ce) crystal gamma ray detector formed by combining LaBr3(Ce) and a photomultiplier, a spectroscope amplifier, a peak holding circuit, a pulse amplitude analyzer and a high and low voltage power supply; the operating platform comprises a power supply converter and a computer; and the spectroscope amplifier receives a pulse signal from the detector, the pulse signal is input into the pulse amplitude analyzer through the peak holding circuit after passing through the spectroscope amplifier, and digital information output by the pulse amplitude analyzer is connected with a 485 communication interface of the computer through a 485 communication interface of the probe, and the cable. The logging instrument can directly measure the characteristic energy spectra of various radionuclides such as a uranium family, a thorium family, potassium and the like in nuclear resource logging, and has the characteristics of high energy resolution, measuring efficiency and stability, and the like.