In order to accurately detect formamide residues in children's floor mats, gas chromatography-mass spectrometry( GC-MS) method was used to verify the ability of formamide detection through the determination of recovery rate of the experimental method. After acetone ultrasonic extraction and concentration, the sample was separated by DB-WAX column, and the formamide was analyzed qualitatively and quantitatively by mass spectrometer. The standard recovery rates (n=6) of the three concentration levels were maintained between 97% ～103%, which were in line with the regulations of 85%～105%. The detection limit(S/N=10) of formamide in children's floor mats was 1.0 g/g, and the linear correlation coefficient was 0.999 in the mass concentration range of 1.11 ～111 g/mL. The experimental results show that the method was accurate, sensitive, precise and linear, and suitable for the detection of formamide residue in children's floor mats. The method was used to determine 50 batches of children's floor mats, and the results showed that the formamide content of 12 batches of products was higher than the limit value of 200 mg/kg, and the formamide content was detected in 17 batches with the highest content reaching 1 010 mg/kg. This method does not need complex pretreatment, is simple and quick to operate, and has great application value in detection.