The invention belongs to the technical field of diesel engine exhaust, and provides a direct-impact-type turbine-behind exhaust device. The direct-impact-type turbine-behind exhaust device is provided with an exhaust volute of which the upper end face is provided with an opening; a partition plate is arranged in the manner of being perpendicular to the bottom face of the exhaust volute; the two opposite side wall faces of the exhaust volute are provided with pits concaved inwards, and the bottom face of each pit is provided with a through hole communicating with an internal cavity of the exhaust volute; a corrugated pipe is arranged in each pit, and each corrugated pipe protrudes out of the corresponding pit; the center of each corrugated pipe is provided with a diffused through hole communicating with the corresponding through hole, and a diffusion pipe which is in clearance fit with each diffused through hole is arranged in the diffused through hole; and the exhaust device is further provided with a divergent pipe connected to an opening of a supercharger turbine. According to the direct-impact-type turbine-behind exhaust device, the structural requirement that two exhaust systems are connected in a small space is met, it is guaranteed that the condition that air flow impacts the wall face at a high speed can not occur as the exhaust systems are low in resistance and flow speed, and a reliable guarantee is provided for the good performance of a diesel engine.