<p>Experimental and numerical tests are used to investigate the uniaxial compression mechanical properties and failure mechanism of coal-rock combinations with different rock-coal combinations (RC) and rock-coal-rock combinations (RCR). The results indicate that the uniaxial compressive strength and elastic modulus of coal-rock combinations decrease with increasing proportions of coal. The uniaxial compressive strength of the combinations is close to the strength of coal when the proportion of coal accounts for more than 40% of the RC and more than 70% of the RCR. When the proportion of coal is less than 70%, the uniaxial compressive strength of the combination gradually decreases with increasing proportion of coal, mainly because the range of the horizontal stress constraint at the interface decreases. The failure of RC combinations under uniaxial compression mainly occurs in the coal component, and it is usually in the form of inverted ‘V’ shear failure or vertical splitting failure. For RCR combinations, as the proportion of coal increases, the failure mode of the combination gradually shifts from the hyperbolic failure mode combined with inverted V-type shear failure to X-type shear failure of the coal component. The research conclusions can provide a theoretical reference for the failure mode and instability behavior of the combination in the coal mining process.</p>