The invention relates to the technical field of 
nuclear radiation detection and provides a multichannel digital 
spectrometer with a function of spectrum stabilization. The multichannel digital 
spectrometer comprises a front end analog circuit, a high speed and high precision 
analog to digital converter (ADC) circuit, a high-speed 
field programmable gate array (FPGA) circuit and a communication module, wherein the front end analog circuit, the high speed and high precision ADC circuit, the FPGA circuit and the communication module are serially connected with one another, a nuclear pulse 
signal enters the 
spectrometer from the front end analog circuit and enters the ADC circuit after 
signal conditioning, the ADC circuit completes 
digital conversion of an 
analog signal, subsequently, the 
signal enters the FPGA circuit to be subjected to 
digital signal processing, and a 
processing result is transmitted to a computer through the communication module. The FPGA circuit provides a 
gain control signal to the front end analog circuit according to the calculation result and receives a comparative result of a high-speed 
comparator in the front end analog circuit. According to the multichannel digital spectrometer with the function of spectrum stabilization, a brand new front end 
analog circuit design and a high speed and high precision ADC are used, the 
processing speed of the digital spectrometer is greatly increased, the multichannel digital spectrometer can be simultaneously connected with at most four 
energy spectrum type detectors, and the application range is more wide.