Due to the limitations of packaging, waveguide structure and other factors inducing the asymmetrical beam quality on fast and slow axis, diode laser is usually used as pump source and power convertor, it is difficult for diode laser to be used as a high- brightness laser source directly. The development of an incoherent beam combining technology-external cavity feedback grating spectral beam combining, which could improve the output optical power density and output beam quality of semiconductor laser, is introduced. A number of important trends in the development of semiconductor laser spectral beam combining technology are summatised, which provides a reference for future development of semiconductor laser spectral beam combining technology.