A method for the quantitation of formaldehyde in infant formula was established by gas chromatography (GC) and validated by gas chromatography-mass spectrometry (GC-MS). The level of formaldehyde pollution in 45 commercial infant formula samples was determined by the proposed method and the risk of dietary exposure to formaldehyde through the consumption of infant formula was evaluated. The sample pretreatment conditions were optimized and the analytical method was assessed in terms of linearity, precision, accuracy, limit of detection (LOD) and limit of quantitation (LOQ). Quantitation was performed using the external standard method. The results showed that the linearity of this method was good in the range of 0–10 μg (r > 0.999), the LOD was 0.1 mg/kg, and the LOQ was 0.3 mg/kg. The average recoveries at spiked levels of 0.3, 0.6 and 3.0 mg/kg were in the range of 88.33%–96.56%, with relative standard deviation (RSD) less than 10%. The formaldehyde content increased with increasing reconstitution temperature above 40 ℃. In order to simulate the actual consumption process, the infant formula samples were detected after being reconstituted with warm water at 40 ℃. It turned out that formaldehyde was found in all samples at levels of 0.38–2.72 mg/kg. The average formaldehyde exposure of infants of different ages was 20.40 μg/kg at 0–6 months, 21.11 μg/kg at 6–12 months and 26.74 μg/kg at 12–36 months.