Experiments on axial compressive property, shear performance along horizontal bed joint and behavior under combined compressive and shear loadings were carried out to study the failure characteristics and failure mechanism of the shale fired heat-insulation block masonry. The results showed that the main cracks were formed nearby the vertical mortar joint when shale fired heat-insulation block were failed under axial compressive and the skin of masonry were fallen close to ultimate load. The main failure pattern of shear along horizontal bed joint of masonry was mainly single shear failure and its failure was obvious brittle failure. There were shear friction failure, shear compression failure and diagonal compression failure under combined compressive and shear loadings. Test average result of axial compressive strength was higher than code values; the average result of shear along horizontal bed joint and shear under combined compressive and shear loadings were lower than calculating values and the formula for were established separately. The strength of shear under combined compressive and shear loading increased with increasing axial pressure. The calculation formula of stress-strain relation of shale fired heat-insulation block masonry was established. Poisson ratio and elastic modulus of shale fired heat-insulation block masonry was proposed.