An inferior coal micro-oil ignition combustor comprises a streamlined air powder separation ring, a bidirectional cyclone oil combustor, a wing-shaped anti-friction block, a primary dense-phase coal powder combustion chamber, a secondary dilute-phase coal powder combustion chamber, a V-shaped cavity backflow blunt body, a circumferential cooling bellows and the like, employs a principle of gas-solid two phase flow separation, a principle of oil flame two-way cyclone ignition, backflow high-temperature flue gas of a blunt body, a principle of energy repeated utilization, a principle of coal powder graded ignition and energy gradual enlargement, forms a power field with low air speed, high density, strong eddy flow, strong backflow in the combustor, and creates favorable condition for firing coal powder, so as to effectively solve the problems of firing difficulty and low burn-out ratio of inferior coal. The combustor is capable of igniting inferior coal of 4 to 10 tons by using oil capacity of 150kg/h, which has an oil-saving ratio more than 80%, service life more than 4 years, and is beneficial for popularization in related industries.