The invention discloses a sloping plate sedimentation basin and needle cylinder type plasma combined treatment device for toxic organic wastewater. The device comprises a tubular plasma reaction vessel, a cylindrical sloping plate sedimentation vessel, a high-voltage electrode and a grounding electrode, wherein the high-voltage electrode and the grounding electrode are connected with the positive electrode and the negative electrode of a power supply respectively. The tubular plasma reaction vessel is sleeved with the cylindrical sloping plate sedimentation vessel, a sloping plate is arranged in an annular area between the cylindrical sloping plate sedimentation vessel and the tubular plasma reaction vessel to form a sloping plate sedimentation area, and a sludge bucket is arranged below the sloping plate sedimentation area. The high-voltage electrode is inserted in the tubular plasma reaction vessel. The device has the advantages of being high in utilization rate, high in continuity, economical, environmentally friendly, stable in operation and the like, has a significant treatment effect especially on high-concentration wastewater likely to flocculate and difficult to degrade, has broad potential application prospects and is expected to be widely applied and popularized in a water body pollution treatment process in the future.