The invention relates to a method for acquiring the airplane vertical occupancy rate. The method comprises the following steps: the acquired flight flow sample data is processed to obtain the data information of all flights; the position information of each way point of the flights on the flight line and the flight information of the flights to pass through each way point are extracted from the data information of each flight; two flights are compared in sequence according to the position information of the way point and the flight information of the flights to pass through each way point to determine the number of the flight pair with collision risk; and the vertical occupancy rate is determined according to the number of the flight pair with collision risk. The flight pair with collision risk does not depend on the individual empiric parameter value, and not adopt the direct statistical method for the complex parameter. Therefore, not only the accuracy of the calculated vertical occupancy rate is high, but also the use is simple and convenient, and the invention is convenient for engineering realization, is favorable for the quantitative description of busyness of the aerial traffic to realize, provides the accurate data basis for the airspace running analysis and the safety assessment, and has wide application prospect.