The complex geological structure of a coal seam is one of the important causes of rockburst. This paper investigates the instability process and precursor characteristics of an ancient fluvial sedimentary microfacies coal seam. The results show the following. (1) When the inclination angle is small, the sample experiences fracture and instability with relatively high peak stress. When the inclination angle is large, the sample experiences slip and instability, and high-energy release under low stress condition. (2) Before the instability of the combined samples, the fracture development clearly results in a low total fault area (A(t)) value, relatively high and obviously low microseismic activity (S) values alternately appear, and the acoustic emission (AE) count and lack of shock (b) value fluctuate significantly. (3) The peak strength of the combined samples decreases with increasing inclination angle. The thickness of the coal is large, the strength of the combined samples is small, and the development and expansion of cracks and energy release are relatively weak. When the loading rate is relatively small, the peak AE count and energy release are relatively large. This research not only enriches the theory of deformation failure and dynamic disaster of complex coal seams, but also provides a reference for early warning of rockburst.

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