Tensile strength of coal naturally exhibit anisotropic characteristics and affected by the spatial distribution of its internal microstructures. Microwave heating realizes auxiliary coal breaking, via the thermal difference generated thermal stress in different material after microwave absorbing. Understanding the tensile strength anisotropy affected by microwave heating is significant for the stability analysis of the working face, the coal pillar, and the roadway, which were assisted excavated by the microwave heating. In this paper, the influence of microwave heating on the tensile failure of coal was experimentally investigated. A series of disc specimens were drilled parallel to the bedding plane, separately heated with different microwave irradiation powers, and then tested under different anisotropy angle conditions. X-ray computed tomography (CT) scanning and acoustic emission (AE) monitoring were employed to investigate the macro- and micro-failure characteristics of coal affected by microwave heating. The result indicates that the tensile strength exhibits a generally increased wave-shaped variation as the anisotropy angle increases from 0° to 90°. Which was verified applicable described by a sine function. The increasing irradiation power reduces the tensile strength and the anisotropy of it, as the irradiation power changes from 0 to 2.0 kW. Microwave heating reduces the percentage of tensile failure cracks generated during the tensile failure process and contributes to more complex macro failure patterns. Microwave heating weakens the connection between the mineral inclusion and the coal matrix, which makes the failure cracks easily propagate during the failure process. This may be the reason that more macro cracks developed along the mineral inclusions, while a lower percentage of tensile failure occurred, under the greater irradiation power condition.