The accurate acquisition of in situ particle detection information in clouds is important in revealing the physical mechanism of cloud precipitation formation, improving the parameterization scheme of numerical weather prediction models, and evaluating the seeding effect of weather modification. Digital holographic measurement technology can obtain three-dimensional positioning information of particles and has advantages, including a wide measurement range (μm to mm), high spatial resolution (mm magnitude), and accurate determination of instrument sampling space. Therefore, it has wide application prospects in cloud microphysics observations. This study summarizes the current situation of holographic cloud particle imagers worldwide. Several key technical issues involved in the development of instruments were analyzed, such as the holographic optical path design, mechanical protection design, and hologram processing. Applications of holographic observations to reveal the freezing mechanism of ice crystals in mixed-phase clouds and microphysical mechanisms in clouds with turbulent mixing were introduced. Finally, certain thoughts and prospects were discussed from the perspective of technology application, which can provide a reference for the development of related instruments and research on cloud microphysics observations.