Currently, UV photolysis technology is seen as an effective method to deal with refractory organic matter or other pollutants because of its mild reaction conditions, strong oxidizing capacity, and other advantages. The shortcomings of the traditional mercury lamps, such as short lifetime, single wavelength, and low luminous efficiency, have limited their application in practical engineering. Microwave electrodeless lamp is a new type of high efficiency light source. It has the characteristics of high photooxidation activity, large spectral range selectivity, and simple device. At the same time, microwave and ultraviolet radiation are combined to greatly enhance the degradation of pollutants. Besides, microwave has the advantages of fast heating, small space occupation, no variation in light intensity, no heat medium and thermal inertia. Firstly, the principle of microwave and microwave-assisted photooxidation were introduced. Secondly, the principle of luminescence of microwave electrodeless lamp was also introduced. The application of electrodeless lamp in the treatment of water and gas and its regeneration of adsorbent were explored. At the same time, its influence factors were summarized, including electrodeless lamp, microwave power, temperature, and dielectric properties. Moreover, suggestions for further studies were also put forward.