The invention relates to a method for preparing nano calcium carbonate particles with different aspect ratios by means of adjusting the number of carbonization times. The method comprises the following steps: adding deionized water at the temperature of 80-85 DEG C into CaO; stirring for reacting for 20-30 minutes; ageing at room temperature; sieving; adding deionized water to obtain a Ca(OH)2 solution; under the condition of a water bath, adding a crystal form control agent into the Ca(OH)2 solution; stirring for dissolution; introducing carbon dioxide gas for carbonization and stirring until a different reaction stage is reached; if carbonization needs to be performed for multiple times, continuously adding carbon dioxide gas after ageing, and stirring until the pH reaches 7; centrifugally washing; and drying, thereby obtaining the nano calcium carbonate particles with different aspect ratios. The method has the characteristics of being simple to operate, low in cost, excellent in repeatability, low in requirement on temperature and the like, the reaction conditions are easy to control and the product quality is good; the prepared nano calcium carbonate particles are uniform in particle size distribution and excellent in dispersibility, and has a good application prospect.