Blue laser diodes currently play a vital role in the processing of nonferrous metals such as copper and gold, as well as their composite materials. The development of high-brightness blue laser diodes is a key focus in the industry, leading to significant attention on high-brightness blue laser diode chips and beam combining technologies. This study reviews recent advancements in high-brightness blue laser diodes in the mentioned areas. It briefly covers the improvements in the brightness of high-brightness blue laser diode chips, as well as the principles behind various beam combining technologies and the related research. The review particularly focuses on blue laser diodes based on grating spectral beam combining, which is currently the most significant technological approach for enhancing brightness. Finally, the study summarizes the challenges associated with high-brightness blue laser diodes and discusses future prospects.