The objective of this paper is to propose a method utilizing lanthanum trifluoromethanesulfonate (La(OTf)₃) as catalyst with the intention of investigating its potential to enhance the efficiency of the hydrolysis reaction of PA66. By systematically regulating the reaction temperature, time and catalyst dosage factors, the optimal hydrolysis conditions were determined. These are found to be a mass ratio of m (La) ∶ m (PA66) ∶ m (H₂O)= 1∶20∶100, reaction temperature of 220 ℃ , and time of 12 h. The conversion rate of PA66 under these conditions reaches 52% , in comparison to the pure hydrolysis conversion rate of 25% . This demonstrates the significant impact of the catalytic system. The molecular weight distribution of the solid-phase products was analyzed by matrix-assisted laser desorption ionisation time-of-flight mass spectrometry (MALDI-TOF-MS), and the results demonstrate that the predominant component is incompletely reacted PA66. Furthermore, electrospray ionisation mass spectrometry (ESI-MS) spectra indicate that the liquid-phase products are dominated by monomers and dimers, with a small amount of water-soluble trimer and tetramer present. The activation energy (E_a) of the reaction is calculated to be 73.76 kJ / mol, which is lower than that of the conventional concentrated sulfuric acid catalytic system. This indicates that La (OTf)₃ demonstrates superior performance in promoting the hydrolysis reaction of PA66.