The invention relates to a pressure analysis device of polyacetylacetonatozirconium precursor fiber during zirconia crystalline fiber preparation. The device comprises an inner container and an interlayer, the inner container is provided with multilayer grid supports for placing precursor fiber, the interlayer is arranged at the outside of the inner container for introducing stead for heating, the top of the inner container is provided with an atmosphere inlet, and the bottom of the inner container is provided with a steam outlet for enriching a ligand acetylacetone. The polyacetylacetonatozirconium precursor fiber is placed in the device at 2-8 atmospheric pressure and 120 DEG C-170 DEG C for analysis processing, so that the acetylacetone ligand in the precursor fiber is efficiently analyzed and separated, and thus the substantial improvement on the quality of zirconia crystal fiber and the recovery of an acetylacetone salt byproduct are realized. According to the device, not only the performance of the prepared zirconia fiber can be greatly improved and the energy consumption cost can be reduced, but also the by-product recovery can be increased, and the green environmental-friendly production of the zirconia fiber can be facilitated.