Abstract: In order to investigate the mechanical properties and failure modes of coal samples from a coal mine under triaxial compression environment, setting up confining pressure gradient of 0.2, 0.4, 0.8, 1.1, 2.0 and 3.0 MPa, the electro-hydraulic servo testing system is used to carry out the triaxial test; fitting analysis for test data, the expression about relationship of peak compressive strength, elastic modulus and confining pressure is established; failure characteristics of coal samples are analyzed, the impact of applying confining pressure on coal samples with different failure modes is discussed. The results show that: the peak compressive strength and elastic modulus increase with the confining pressure, and the variation of peak compressive strength and elastic modulus increases first and then decreases with the increasing of confining pressure; the peak strength and confining pressure present a logarithmic distribution law; while the elastic modulus increases exponentially with the increase of confining pressure; with the increase of confining pressure, the failure modes of coal samples may be the tensile-shear (tensile dominated)-shear failure mode.