Abstract: Chemical grade MTBE is mainly used for the production of polymerization grade isobutene, all types of impurities in MTBE should be controlled strictly. However, the detection limit of the existing method SH/T 1550-2000 is 0.02% (mass fraction) which cannot meet the analysis requirements. In this study, the advanced heart cutting technology is used, in which the components difficult to separate in nonpolar capillary chromatographic column are cut out and sent to the second polarity capillary column for separation. Double hydrogen flame ionization detector (FID) is used, and the calibration areas are normalized. The main components difficult to separate, such as methanol and isobutene, t-butanol and 2- pentene, methyl butyl ether and 2-butyl alcohol can be separated better and detected by heart cutting method, and the detection limit is improved to 0.002% (mass fraction).