In this paper, the research work on the early lightning spectrum is briefly reviewed, and then the latest progress of lightning spectrum research in the recent 20 years is reviewed in two stages. In the 1960s and early 1970s, although the lightning spectrum obtained by film cameras had many shortcomings, many important research results were achieved, which not only laid a solid foundation for the later research work of lightning spectrum but also pointed out the direction of development. Since 2001, the slit-less grating spectrograph assembled by ordinary digital camera has been used to study the lightning spectrum in China. Although an ordinary digital cameras solve the problem of film cameras, the shooting speed is slow (50 frames per second), and the nature of the lightning return stroke channel can only be studied in this time range. Nevertheless, these works once again promoted the development of lightning spectrum research, so the international gradually began to pay attention to lightning spectrum research. In 2011, Warner et al. recorded the spectrum of the cloud-ground lightning stepped leader with a slit-less spectrometer assembled with a high-speed camera, which improved the shooting speed to a certain extent (10 000 frames per second). Since 2012, the slit-less grating spectrograph integrated with a high-speed camera as a recording system has been used in China to capture the lightning spectrum, and a lot of research work has been carried out on the radiation spectrum at different stages of the lightning channel under the condition of higher temporal resolution, and several eye-catching research results have been achieved. They mainly include the spectral study of the stepped leader, dart leader and return stroke of the natural lightning, as well as the ball lightning and the lightning channel core. In 2017, Warner reported the spectra of artificially triggered lightning initiation, dart leader, return stroke, and continuous current at a wavelength range of 380~620 and 620~870 nm with a time resolution of about 1.5 microseconds, but the range was too small to capture the spectra of only one part of the lightning channel. Therefore, how to obtain spectral data with the higher spatial and temporal resolution is an urgent problem in lightning spectrum research.