<p>The microseismic monitoring technology is an effective tool for real-time monitoring of the rock fracture process and then providing early warning for geological disasters in rock engineering. Numerical simulation is an important means of assisting the microseismic monitoring to reveal the evolution characteristics of microseismic events. However, current numerical simulation methods for microseismic phenomena can only capture the number and tensile-shear failure mechanism of microseismic events but not the microseismic signals during rock fracture, resulting in fundamental and theoretical differences from on-site microseismic monitoring. To address this, this study proposes a novel numerical simulation method for microseismic signals based on the bonded particle model (BPM), which can simulate the entire process of generation, propagation and monitoring of microseismic signals induced by rock fracture, and a practical case of unstable rock collapse was taken as an example to verify the proposed simulation method. Firstly, a bonded particle model of unstable rock was constructed, and the influence of loading path and local damping coefficient on the simulation results of microseismic signals was investigated. Then, the accuracy of the numerical simulation method for microseismic signals was validated through the on-site microseismic signals. The study results indicate that the stress waves generated during the process of unstable rock collapse can be accurately and timely captured by setting appropriate model parameters. The waveform, dominant frequency and spectrum of simulated microseismic signals exhibit similar evolution characteristics to those of on-site microseismic signals, thereby confirming the accuracy of the proposed simulation method. The numerical simulation method for microseismic signals proposed in this study provides a new approach for the theoretical and numerical investigation of microseismic monitoring technology.</p>