The invention relates to a method for synthesizing hydrochloric acid itraconazole. The problems that the yield is low, product stability is poor, quality is poor, cost is high, and the environment is polluted can be effectively solved. The method comprises the steps that the itraconazole is added to an organic solvent and is mixed evenly, the mass ratio of the organic solvent to the itraconazole is 1-5:1, hydrochloric acid with the mass concentration of 36 percent-38 percent is dropwise added, the mass ratio of the organic solvent to the hydrochloric acid is 2-8:1, stirring is carried out for 3-6 hours, temperature is reduced to 10-30 DEG C, filter is carried out, a crystalline is obtained, the crystalline is washed with the organic solvent two to three times, drying is carried out, and the hydrochloric acid itraconazole is obtained. Hydrogen chloride gas is not added any more, and potential safety hazards for preparing the hydrogen chloride gas is removed. Corrosion on equipment is reduced. Product quality is improved, the product yield can reach 98.5 percent-100 percent, and purification is not needed. Unit energy consumption is reduced. Production cost is lowered. The dissolution rate and stability of preparations are improved. Environmental protection, worker body health and large-scale industrial production are facilitated.