The invention discloses a method for treating ammonia containing wastewater through simultaneous nitrification and denitrification. The method comprises the following steps: firstly, cultivating denitrifying granular sludge; and secondly, using the denitrifying granular sludge to treat ammonia containing wastewater through simultaneous nitrification and denitrification. The cultivating method of the denitrifying granular sludge comprises the following steps: firstly, inoculating seed sludge in an aerobic reactor, and performing accumulation culture to the aerobic sludge with high ammonia-nitrogen and low chemical oxygen demand (COD) wastewater; secondly, separating and screening aerobic denitrifying bacteria to perform domestication and cultivation; and thirdly, inoculating the domesticated and cultivated aerobic denitrifying bacteria in the denitrifying granular sludge to cultivate and obtain the finished denitrifying granular sludge. The invention adopts the domesticated and cultivated simultaneous nitrification and denitrification sludge treatment catalyst to treat ammonia containing wastewater, and has the characteristics of high removal rate of contaminants, low energy consumption and material consumption and the like; and nitrification and denitrification can be completed in the same reactor, and the short-range simultaneous nitrification and denitrification technology can be applied in actual wastewater treatment.