Based on the second method of GB 5009.270—2016, a more convenient and efficient gas chromatography method was established for the detection of inositol content in infant formula milk powder. Compared with the second method of GB 5009.270—2016, this method can shorten the drying time and the derivative time on water bath through improving the extraction solvent and extraction methods, the purification methods, the drying methods of the derivatives and the adding sequence and proportion of derivative reagent. What’s more, this method can also reduce the retention time and analysis time in inositol’s detection by optimizing the testing parameters of gas chromatography instruments. The results showed that the detection limit of the improved method was 1 μg/mL, and the recoveries of three level marking test ranged from 97.4% to 100.5%, this method also simplifies the sample pretreatment operation and shorten instrumental analysis time from 63 min to 20 min compared with the national standard method. It can realize the batch processing and meet the requirements of the laboratory detection with large samples.