The invention relates to a composite-type scintillator gamma spectrometer, and belongs to the technical field of ray detection. The basic structure of the gamma spectrometer is that a scintillator is placed in the center position to serve as a main crystal; another type of scintillator, the luminescence decay time difference between which and the scintillator above is large, is arranged around the main crystal to serve as an auxiliary crystal; and a photomultiplier are coupled with the two scintillator crystals to collect scintillation photons generated in the scintillators. Through an "inside-circle outside-ring" structure, the scintillation photons can be read directly from the two crystals; meanwhile, the auxiliary crystal closely surrounds the side surface of the main crystal, and thus the scattered photons emitted from the side surface almost can be detected; the side surface area is large, and thus anti-Compton efficiency of such structure is relatively large; and except the anti-Compton effect, the auxiliary crystal on the side surface can also help to remove other backgrounds from side incidence, thereby greatly improving radiation detection capability in the main direction.