The invention discloses an itraconazole inhalation powder aerosol and its preparation method. The inhalation powder aerosol is prepared by using itraconazole and 20-80mass% of a carrier, and the carrier is at least one of lactose, mannitol, inulin and amino acids. The method comprises the following steps: mixing itraconazole with the carrier, adding the obtained mixture into a double screw hot melt extruder, setting the extrusion temperature at 150-170DEG C, starting screws after the preset temperature is reached, and carrying out strip extrusion under a screw rotating speed of 150-200r/min, cooling obtained strips in a dryer to room temperature, crushing by using a micro pulverization machine, and micronizing by using an airflow crusher to obtain the above powder. The inhalation powder aerosol has the advantages of good physical stability, good powder fluidity, high deposition amount at effective positions, high dissolution rate, fast dissolution speed, small drug dose, and low incidence rate of toxic side effects; and the method has the advantages of simple technology, no organic solvents, antiseptics or other impurities in the process, good reappearance and easy industrial production.