This in-rack air-liquid hybrid cooling liquid distribution unit (CDU) integrates the control system, power system, buffering system and heat exchange system. It is specifically designed for liquid cooling scenarios in high-density server cabinets and complies with B-level data center standards. It can be deployed in 19-inch standard cabinets and provides a maximum cooling capacity of 18kW for a single cabinet. The core power adopts a dual-pump one-out-of-two redundant configuration, and power supply supports dual power input. The communication interface is equipped with redundant design. The entire link ensures the continuous operation of the system. The entire pipeline is made of SUS304 stainless steel, compatible with various cooling media such as deionized water, ethylene glycol, and propylene glycol, with strong medium adaptability and long service life. The coolant distribution unit adopts a closed-loop architecture, divided into two circuits: the primary side gas-liquid heat exchange and the secondary side medium circulation. It is the core equipment for achieving air-liquid conversion in small and medium-sized liquid cooling data centers and distributed computer rooms.