The key technology o f direct-liquid-cooled bas ed disk solid-state laser (direct-liquid-cooled thin-disk solid-state laser ) is detailedly studied.It includes the design of the channel structure as well as the clamping method for the gain medi um.The design of the channel structure in the gain module is mainly based on the state of the flow field and the heat transfer capacity of the channel.The influences on the thermal str ess and the maximum permissible pump power of the gain medium by “soft clamping” and “har d clamping” are compared and analyzed.The calculations show that the pump power with “soft clamping” on gain medium is about 8times higher than that of “hard clamping”.Finally,th e key technologies are analyzed and summarized based on the configuration of the 1kW level direct-liquid-cooled thin-disk solid-state laser developed by our research g roup.