The utility model discloses a destabilizing separation disposal device for waste drilling fluid. The destabilizing separation disposal device for the waste drilling fluid comprises a sludge pump, a composite tank unit, a fluid supplying pump, a centrifugal machine, a solid phase storage slot, a destabilizing agent storage tank and a coagulant aid storage tank; the composite tank unit is formed by a destabilizing bin, a liquid phase collecting bin and a liquid phase collecting standby bin which are independent from each other; the slurry pump is used for conveying the waste drilling fluid to the destabilizing bin; the fluid supplying pump is used for conveying the waste drilling fluid subjected to the destabilization in the destabilizing bin to the centrifugal machine; the centrifugal machine is placed on the upper end of the destabilizing bin; a solid phase outlet of the centrifugal machine is connected with the solid phase storage slot; a liquid phase outlet of the centrifugal machine is respectively connected with the destabilizing bin, the liquid phase collecting bin and the liquid collecting standby bin; the destabilizing agent storage tank and the coagulant aid storage tank are used for conveying corresponding agents to the destabilizing bin. The destabilizing separation disposal device for the waste drilling fluid integrates agent adding, destabilizing and solid-liquid separating, the solid-liquid separation disposal efficiency is improved, the occupation area is small and the structure is simple and reliable.