The invention relates to the technical field of machining, in particular to a cutter wear estimating and monitoring method and system based on characteristic fusion. The method comprises the steps ofdata flexible acquisition, working condition division, data preprocessing, characteristic extraction, characteristic fusion and estimation and monitoring. The system comprises a working condition division module, a data preprocessing module, a characteristic extraction module, a characteristic fusion module, an estimation and monitoring module and a self-learning module serially connected in sequence. The method and the system can realize multi-signal, multi-working-condition and multi-dimension fusion of original signals to obtain characteristic indexes capable of comprehensively reflecting the cutter wear state for estimating cutter real performance state and change rules to give more precise timely prewarning, alarm and feedback optimization policies. Through improvement of cutter wearonline estimation and monitoring performances, the machining problems caused by cutter wear are gradually solved, and the cost reduction, the quality improvement and the efficiency improvement in themachining process are finally achieved.