The invention discloses a visual testing column device for studying the blockage behavior of a fuel assembly. The visual testing column device comprises a lower chamber, a reactor core testing plate and an upper chamber. The reactor core testing plate is provided with a drain hole for making the upper chamber communicated with the lower chamber. A diversion part which can make fluid with chip impurities fully mixed before the fluid enters a lower pipe base of the fuel assembly is arranged in the lower chamber. In the technical scheme, the diversion part in the lower chamber of the visual testing column device can make the fluid with chip impurities fully mixed before the fluid enters the lower pipe base of the fuel assembly, it is ensured that chip impurities can all reach the fuel assembly without depositing in the lower chamber, and the security of the test result is effectively improved. In addition, the visual testing column device is visual within the whole range outside a test piece of the fuel assembly, the blockage behavior of the chip impurities on the fuel assembly can be conveniently observed, and visuality is high.