Due to a large number of photons irradiated by the fuel assemblies after radiation in the reactor,the data acquisition and image reconstruction will be interfered seriously for the nuclear fuel assembly non-destructive testing system.Therefore,in process of the fuel assembly NDT system Due to a large number of photons irradiated by the fuel assemblies after radiation in the reactor, the data acquisition and image reconstruction will be interfered seriously for the nuclear fuel assembly non-destructive testing system. Before, in process of the fuel assembly NDT system