Objective To understand the pollution level of perchlorate and chlorate in infant formula milk powder in Inner Mongolia evaluate the dietary intake risk of perchlorate and chlorate in infants， and provide a scientific basis for guiding the healthy diet of infants in Inner Mongolia.Methods A total of 539 infant formula milk powder sold in each segment in Inner Mongolia were collected， and 254 milk powder flushing water （drinking water that may be used in the flushing and mixing of milk powder） were collected. The contents of perchlorate and chlorate in infant formula milk powder and milk powder washing and mixing water were detected by ultra-performance liquid chromatography-tandem mass spectrometry （UPLC-MS/MS）. Based on the consumption data of infants and young children in Inner Mongolia in the 2015 China Infant Food Consumption survey data， the risk of dietary intake of perchlorate and chlorate in infant formula milk powder in Inner Mongolia was calculated by simple distribution assessment and cumulative exposure assessment.Results The overall detection rate of perchlorate in infant formula milk powder was 92.39% （498/539）. The detection value was not detected up to 89.30 μg/kg， with an average of 14.45 μg/kg and a median of 9.00 μg/kg. The overall detection rate of chlorate was 73.10% （394/539）， and the detection value was not detected up to 1 061.00 μg/kg， with an average of 93.25 μg/kg and a median of 45.50 μg/kg. The overall detection rate of perchlorate in milk powder was 67.32% （171/254）， and the detection value was not detected up to 26.59 μg/L， with an average value of 1.25 μg/L. The overall detection rate of chlorate was 30.71% （78/254）， and the detection value was not detected up to 927.66 μg/L， with an average value of 24.03 μg/L. The health risk of perchlorate and chlorate intake through milk powder was assessed as low for infants aged 0 to 36 months. Furthermore， the exposure of the high consumer population （P95） did not exceed the health guidance value.Conclusion There is perchlorate and chlorate contamination in infant formula powder in Inner Mongolia. However， under the current pollution level， the health risk of perchlorate and chlorate ingestion through milk powder is low for infants under the age of 0-36 months. In addition， the exposure level of the high consumption group （P95） did not exceed the health guidance value， and the health risk was low. The exposure level of P95 in infants aged zero to six months is higher， and further attention should be paid to their health risks.