The invention discloses a double-LaBr3 crystal detector element energy spectrum logger based on a controllable neutron source. The double-LaBr3 crystal detector element energy spectrum logger comprises a cylindrical shell, wherein the cylindrical shell is internally provided with a LaBr3 detector I and a LaBr3 detector II from top to bottom, the controllable neutron source is connected with a photomultiplier at the top part of the LaBr3 detector I, a chromium foil is arranged between the LaBr3 detector I and the LaBr3 detector II, and the photomultiplier, the LaBr3 detector I, the chromium foil and the LaBr3 detector II are arranged in a boron sleeve body which is positioned in the cylindrical shell; a tungsten shielding body is arranged between the controllable neutron source and the boron sleeve body, and the controllable neutron source is connected with a neutron detector through a neutron acceleration part. According to the double-LaBr3 crystal detector element energy spectrum logger based on the controllable neutron source, disclosed by the invention, by utilizing the controllable neutron source and the double LaBr3 detectors with high resolution, the content measuring accuracy of elements such as C and Mg and the longitudinal resolution can be increased, the measurement information can be increased, and the purpose of simultaneously determining parameters of stratum element content, mineral content, porosity degree and the like can be realized; the double-LaBr3 crystal detector element energy spectrum logger has the characteristics that the environmental hazard is reduced, effective stratum information is enriched, and the like.