The invention belongs to the technical field of communication, and discloses a VoLTE accurate switching method and system based on user perception, and the method comprises the steps: determining a KPI index and a convergence threshold of a perception dimension through the hierarchical mapping of a KQI and a KPI index according to the perception dimension of a user, building a KPI difference portrait model, and carrying out the comprehensive scoring of a small service and a target cell; if the total weight score of the serving cell exceeds the total weight score of the neighbor cell, startingan emergency switching process; and when the serving cell does not reach the condition of starting the emergency switching threshold, namely the total weight score is smaller than the total weight score of the adjacent cell, performing pilot frequency inter-system switching based on A2 + A4/A2 + A5/A2 + B2 according to a normal switching process. According to the invention, the emergency switchingof the perception dimension is introduced to enable the UE terminal to quickly start the emergency switching when the perception of the serving cell is reduced, thereby effectively avoiding the problems of packet loss, interruption, single pass, call drop and poor MOS quality caused by the degradation of the UE terminal in the aspects of interference, quality, load, distance and the like in the prior art, and improving the voice quality.