The invention relates to a method for culturing shortcut nitrification granular sludge by combining the dual inhibition of free ammonia (FA) and free nitrous acid (FNA), and belongs to the technical field of the biological denitrification of wastewater. The method comprises the following steps of: inoculating flocculent active sludge to a sequencing batch reactor (SBR), and pumping wastewater which contains chemical oxygen demand (COD) and ammonia nitrogen and serves as inflow from the bottom of the reactor; after a liquid level is reached, starting a stirrer and a blast blower to perform aerobic nitration, degrading organic matters and oxidizing the ammonia nitrogen to form nitrites; after the nitration is finished, stopping aerating and stirring, precipitating to obtain supernatant containing the nitrites, and discharging sewage from a drainage valve, wherein in the culture conditions, the temperature of the reactor is between 25 and 30 DEG C, NaHCO3 solution is added after aeration is performed for 30 minutes, so that the pH value is kept between 7.5 and 8.0, dissolved oxygen is between 3 and 5 mg/L, upflow is provided at the speed of between 1.0 and 1.5 cm/s, and sludge age is between 12 and 15 days; and culturing for 30 to 50 days to obtain the shortcut nitrification granular sludge. By the method, the removal efficiency of a denitrification system can be improved effectively, oxygen supply and denitrification carbon sources can be saved, the yield of the sludge can be reduced, the volume of the reactor can be reduced, and the construction and operating cost can be saved.