The invention relates to a method for controllably preparing oxide powder of titanium. The method comprises the steps of weighing titanium powder and perchlorate, mixing the titanium powder and the perchlorate, then, putting the mixture into a vacuum-tight quartz tube, and carrying out a reaction for 10 to 30 hours at the high temperature of 400 DEG C to 1,100 DEG C, thereby obtaining the oxide powder of titanium. According to the method, a halide is produced during the reaction and can serve as a cosolvent of the reaction; and due to the addition of the halide cosolvent, the diffusion is accelerated, the reaction time is greatly shortened, and the crystallinity and purity of oxides of transition-metal titanium are guaranteed.