Abstract: Neutron imaging is one kind of non-destructive testing（NDT） technique. It can be used to test the defects of pellets, confirm the enrichment of the ²³⁵U, investigate the burnable poison, fix the position and measure the hydrogen in claddings, and so on. Traditional neutron imaging technique gets two dimensions neutron images. It can not be used to test the shape of the defects, the distribution of the pellets, and the condition of the broken cladding. The three dimension neutron imaging quantitative NDT method to test the nuclear fuel rods was presented in this paper, and the experiments were carried out at China Advanced Research Reactor（CARR）and HZB. The three dimension quantification of the defects can obtain 3D image of the internal impurity and measure the parameters. The three dimensions quantification of the hydrogen in the cladding can measure the hydrogen content in almost all the positions in the cladding.