During the processes of coal combustion and gasification, the fragmentation of coal particle occurs throughout the whole reaction process. Coal particles fragment due to different reasons at different residence times, and the fragmentation behavior and particle size distribution variations caused by different mechanisms are also different. However, the fragmentation mechanisms and applicable models at different residence times are yet not clear. In order to investigate the fragmentation behavior of different coals and semi-cokes at different residence times, coals ofdifferent ranks including anthracite, bituminous coal, lignite and the corresponding semicokes were used as test samples for the high-temperature fragmentation experiments carried out in a horizontal-chamber furnace at 1 473 K under nitrogen atmosphere. In addition, a particle thermal stress model was developed with ANSYS finite element analysis software, and the fragmentation mechanism of different coals and their semicokes were analyzed based on the experimental and numerical simulation results. The simulation results show that the thermal stress induced primary fragmentation should occur in less than 2 s after heating for anthracite and different semicokes with low volatile matter content. As expected, the high-temperature fragmentation experiment also shows that these samples indeed only suffer thermal stress fragmentation in the initial 2 s. Bituminous coal and lignite continuously release volatiles during the residence time of 10 s, and the primary fragmentation occurs mainly due to the devolatilization. For the bituminous semicoke and lignite semicoke, numerous weak connections are produced during the pretreatment pyrolysis process, and obvious secondary fragmentation is observed in 6-10 s, and in the later period of the experiment, the fragmentation severity of the two semicoke samples is greater than that of the raw coal samples.