NOVELTY - A comprehensive process for use of carbonaceous organic matter comprises carrying out high-pressure hot water/super-critical water gasification sub-method and carrying out polygeneration sub-method; where the high-pressure hot water/super-critical water gasification sub-method comprises: (a) reacting high-concentration slurry of carbonaceous organic matter; (b) depressurizing and continuously discharging; (c) performing gas/liquid solid separation; and (d) performing liquid/solid separation, preparing the liquid product and solid residue, and discharging continuously.    USE - The comprehensive process is useful for carbonaceous organic matter (claimed).    ADVANTAGE - The comprehensive process converts the carbonaceous organic matter into clean chemical product comprising methane; thus, it forms an ecological cycle mode for developing and using carbonaceous organic matter resource.    DETAILED DESCRIPTION - A comprehensive process for use of carbonaceous organic matter comprises carrying out high-pressure hot water/super-critical water gasification sub-method and carrying out polygeneration sub-method; where the high-pressure hot water/super-critical water gasification sub-method comprises: (a) reacting high-concentration slurry of carbonaceous organic matter in a reactor (4) in the presence of catalyst and under high-pressure hot water or super-critical water state, and generating reaction product; (b) depressurizing and continuously discharging the reaction product into the first separator (6); (c) performing gas/liquid solid separation on the reaction product in the first separator, preparing gas product and liquid solid mixture; where the gas product contains combustible gas; discharging the gas product, and discharging the liquid solid mixture into the second separator (7); and (d) performing liquid/solid separation on the liquid solid mixture in the second separator, preparing the liquid product and solid residue, and discharging continuously. An INDEPENDENT CLAIM is a comprehensive system using carbonaceous organic matter, comprising a high-pressure hot water/super-critical water gasification sub-system and a polygeneration sub-system; where the high-pressure hot water/super-critical water gasification sub-system comprises a reactor (4), a first separator (6), and a second separator (7); where the device for depressurizing and continuously discharging the materials is arranged between the rector and the first separator, or between the first separator and the second separator.    DESCRIPTION OF DRAWING(S) - The drawing shows a schematic diagram of the comprehensive system using carbonaceous organic matter.    Reactor (4)    First separator (6)    Second separator (7)