Nuclear fuel burnup depth measuring device based on active neutron space intensity distribution

The utility model discloses a nuclear fuel burn-up depth measuring device based on active neutron space intensity distribution, which comprises a compact type DD neutron source, a neutron moderation body, a gamma shielding body, a conical neutron collimation hole channel and a thermal neutron image detector system, and the compact type DD neutron source is sequentially wrapped by the neutron moderation body and the gamma shielding body. A big-end-up conical neutron collimation hole channel is vertically formed in the neutron moderation body above the DD neutron source, and a thermal neutron image detector system is installed at the upper end of the conical neutron collimation hole channel. The reaction sections of different elements in the thermal neutrons and the nuclear fuel are different, so that the flux of neutrons which penetrate through a nuclear fuel element sample in the conical neutron collimation hole channels is spatially different; and measuring the fuel consumption depthspace distribution and th