The invention discloses a nuclear detection simulation device based on a nanosecond light source and a nuclear signal inversion technology. The nuclear detection simulation device comprises an upper computer, a ZYNQ SoC processor, a synchronous clock, a DDR3, an SD card (TF-CARD), an LCD display screen and a simulation nuclear pulse signal output channel. An electronic circuit and a nuclear pulse current signal are used for driving a blue light LED to emit a nuclear pulse light signal, and a scintillator is simulated to receive gamma radiation for luminescence; moreover, a point source, a surface source, an organic scintillator detector, an inorganic scintillator, scintillation efficiency, detection efficiency, a radioactive source, fast components, slow components, multi-type nuclear pulse signals, a nuclear pulse statistical fluctuation phenomenon, an electron pair effect, a Compton effect, a photoelectric effect and radiation of the scintillator can be simulated, a corresponding energy spectrum curve is generated, and pulse signal accumulation is otuput; generation of a spectral line and output of an environment background spectral line are simulated; and 3D visual operation is achieved, and the nuclear signal detection process can be demonstrated in an animation mode. Therefore, the device can be used as professional test equipment and also can be used as a teaching instrument.