The invention provides a method for preparing gasified coke from oil tank bottom sludge by coupling treatment. The method comprises the following steps: 1, mixing low-rank coal into coking coal in a high proportion to obtain mixed coal, and sequentially carrying out grinding, screening and drying treatments; 2, feeding into a pyrolyzing furnace for pyrolysis at low temperature to obtain oil gas and hot semi-coke, reclaiming oil gas to obtain coal tar, and drying raw material coal by using fixed gas as gas fuel; 3, heating and dehydrating the oil tank bottom sludge, adding partial hot semi-cokefor tempering treatment to obtain tempered oil sludge; 4, mixing and pyrolyzing the tempered oil sludge and the rest hot semi-coke; and 5, preparing the gasified coke by utilizing pyrolysate. According to the method, the gasified coke is prepared by utilizing mixed coal of high-proportionally mixed low-rank coal and the oil tank bottom oil sludge, an oil product with a high additional value is extracted, a novel way is opened for large-scale utilization of low-rank coal, the problem of over capacity in the coking industry can be effectively solved, the coking production cost can be reduced, and resource treatment of oil tank bottom oil sludge can be realized.