As a new type of unipolar semiconductor laser, the quantum cascade laser (QCL) has a peak emission wavelength in the mid-infrared band (25~25 μm), and has the unique advantages that traditional semiconductor lasers do not have, such as high power, narrow linewidth and fast response rate. The infrared absorption spectroscopy of QCLs has high detection sensitivity and is very suitable for the detection of gas molecules with the characteristic spectrum in the mid-infrared band and can be widely used in the detection of low-concentration gas such as trace gas, respiratory gas, combustion gas, biochemical gas, automobile exhaust, industrial waste gas and pesticide residue gas. Therefore, the use of QCL to detect gas molecules is of great significance in non-invasive medical diagnosis, environmental monitoring, and industrial and agricultural production. Since the invention of QCL at the end of 20th century, the performance of room temperature laser has been greatly improved, and a variety of QCLs have appeared, which also makes the infrared absorption spectroscopy of QCLs greatly developed. In fact, many laser spectroscopies have been developed and applied before the invention of QCL. These include direct absorption spectroscopy (DAS), wavelength modulation spectroscopy (WMS), cavity ring-down spectroscopy (CRDS), cavity enhanced absorption spectroscopy (CEAS) and photoacoustic spectroscopy (PAS) and other related technologies. While the use of QCL as the light source extends the detectable band to a large extent, and also increases the detection limit to some extent. This paper reviews the research status and development trends of infrared absorption spectroscopy of QCLs at home and abroad, and analyzes the bottlenecks encountered in the development process and the solutions obtained in the later stage. The principle and application of various methods are introduced in detail, and the advantages and disadvantages in the measurement are pointed out. At the same time, the field trace gas detection is briefly summarized. Finally, the application and development of infrared absorption spectroscopy of QCLs in the detection of trace gases in the future are prospected. It is pointed out that with the rapid development of infrared absorption spectroscopy, these methods can be more effectively improved and developed with high sensitivity, high integration and high timeliness.