Extreme high-speed laser cladding (EHLC, Extreme High-Speed Laser Cladding) has attracted attention in material surface modification, due to its high energy density (3 kW/cm²), high deposition rates (20–500 m/min), and notable coating performance. However, the rapid heating and cooling inherent to EHLC can introduce stress concentrations within the coating, resulting in defects such as cracks and porosity that may degrade performance. Process optimization is essential for minimizing these defects and advancing coating quality. This paper reviews current research in EHLC technology, beginning with an overview of its fundamental principles and criteria for cladding material selection, including powder characteristics. The effects of processing parameters, such as laser power, scanning speed, and overlap ratio, on coating quality are analyzed alongside established optimization methods. The influence of external field-assisted technologies on coating properties and their mechanisms for regulating microstructures have been discussed. Finally, future trends in EHLC optimization are identified, with the goal of supporting broader adoption in material modification.