Abstract: The unregulated emissions (aldehydes and ketones, benzene, polycyclic aromatic hydrocarbons and other toxic substances) testing of alternative fuels alcohol and ether is still in the exploratory stage. This research summarizes on the detection of unregulated emissions from home to abroad in recent years, focuses on the four more mature testing techniques, including chromatography, mass spectrometry, infrared technology, as well as hyphenated techniques, respectively described their advantages, disadvantages and testing principle. Finally, the paper makes a summary on the development direction of unregulated emissions testing.