Cell lasers is a frontier interdisciplinary research field of laser photonics and life sciences, the principle of which is that, under the optical feedback of the cavity, the weak signal can be oscillated and amplified via the combination of fluorescent protein, bio-compatible fluorescent dye and luciferin into cells in the fluidic environment. We present a detailed discussion about the research status and basic principles of Fabry-Perot cavity and whispering-gallery-mode microcavity. Laser-based detection can effectively enhance the sensitivity and resolution compared with the tradition fluorescence-based detection, benefitting from the feedback amplification of cavity. The physiological changes inside cells are studied with the analysis of the spectra and modes of the cell laser emission simultaneously. It'll provide new technologies and design ideas for medical diagnosis, three-dimensional super-resolution imaging of biomaterials and integrated light source research.