The invention relates to a cyclone separator for gasifying powdered coal. The cyclone separator comprises a pressure-bearing shell, a pressure-bearing shell inner mold flow field and an outlet center pipe, wherein an ash discharging port is formed in the bottom of the pressure-bearing shell, a tangential inlet is formed in the upper part of the pressure-bearing shell, and an outlet pipe is arranged at the top of the pressure-bearing shell; the pressure-bearing shell inner mold flow field is defined by a wear-resistant heat-insulation lining arranged in the pressure-bearing shell; and the top of the outlet center pipe leads to the outlet pipe, and the lower part of the outlet center pipe extends into the upper part of the cyclone separator inner mold flow field. Compared with the prior art, the cyclone separator is internally arranged and the pressure-bearing shell inner mold flow field is formed by integrally casting with the wear-resistant heat-insulation lining, so that the problem that gas phase and solid phase are difficult to be separated under the conditions of high temperature, high pressure and high content of dust in the gasification process of the powdered coal is solved, and meanwhile the operation stability of industrial equipment is ensured.