This article summarizes the research progress of common aperture coherent beam combining based on diffraction optical elements domestically and abroad, starting from the basic principles of diffraction optical elements, and focusing on the two application fields of continuous waves and pulsed waves. Domestically, the Shanghai Institute of Optics and Fine Mechanics has achieved the synthesis of both continuous and pulsed light. Continuous light output of 206 W was achieved with a beam quality of 1.38 and a beam combining efficiency of 29.6%; pulsed light output of a nanosecond-level pulse coherent combining beam with a peak power of 1.02 kW and a repetition frequency of 2.2 MHz was achieved, beam combining efficiency is 61%. Abroad, 4.9 kW coherent beam combining output has been achieved in continuous light, with a beam coupling efficiency of 82%; in the case of pulsed light, a femtosecond-level pulsed coherent beam combining beam with an average power of 150 mW and a repetition frequency of 100 MHz has been achieved, with a beam coupling efficiency of 83.4%. Finally, the future development of laser coherent beam combining technology based on diffraction optical elements is discussed, and it is believed that in the near future, diffraction optical element-based coherent beam combining technology will continue to develop, gradually break through technical bottlenecks, and lay a solid foundation for more application fields.