A working substance contacted cooling system for computer and data center, wherein the system comprises: a server cabinet; a heat-conducting liquid working substance with good insulation; a liquid working substance box arranged at a bottom of the server cabinet; a liquid working substance cooling device configured to cool the heat-conducting liquid working substance with good insulation in the liquid working substance box; a main conduit dispenser vertically arranged, which is in communication with the liquid working substance box through a main conduit; and a liquid working substance pump arranged in or outside the liquid working substance box and the liquid working substance pump is in communication with the main conduit dispenser; and the system further comprises: a plurality of partition plates with holes or grooves, which are parallelly and horizontally arranged at different heights, and on which server components are mounted; a plurality of liquid working substance spraying pipes, a plurality of spray orifices being uniformly arranged on each said liquid working substance spraying pipe, each said liquid working substance spraying pipe being horizontally arranged above the server components at the different heights respectively and being in communication with the main conduit dispenser; spraying directions of the spray orifices being corresponding to positions of the server components; a top of the liquid working substance box is opened to allow heat-conducting liquid working substance with good insulation from the liquid working substance box sprayed on the server components to fall back into the liquid working substance box and the working substance contacted cooling system is configured that no phase change occurs in the process of heat transferring when the heat-conducting liquid working substance with good insulation directly contacts the server components that need heat dissipation. a server cabinet; a heat-conducting liquid working substance with good insulation; a liquid working substance box arranged at a bottom of the server cabinet; a liquid working substance cooling device configured to cool the heat-conducting liquid working substance with good insulation in the liquid working substance box; a main conduit dispenser vertically arranged, which is in communication with the liquid working substance box through a main conduit; and a liquid working substance pump arranged in or outside the liquid working substance box and the liquid working substance pump is in communication with the main conduit dispenser; and the system further comprises: a plurality of partition plates with holes or grooves, which are parallelly and horizontally arranged at different heights, and on which server components are mounted; a plurality of liquid working substance spraying pipes, a plurality of spray orifices being uniformly arranged on each said liquid working substance spraying pipe, each said liquid working substance spraying pipe being horizontally arranged above the server components at the different heights respectively and being in communication with the main conduit dispenser; spraying directions of the spray orifices being corresponding to positions of the server components; a top of the liquid working substance box is opened to allow heat-conducting liquid working substance with good insulation from the liquid working substance box sprayed on the server components to fall back into the liquid working substance box and the working substance contacted cooling system is configured that no phase change occurs in the process of heat transferring when the heat-conducting liquid working substance with good insulation directly contacts the server components that need heat dissipation.