The invention relates to a diesel engine, in particular to a multi-starting mode layout structure of the diesel engine. The multi-starting mode layout structure mainly solves the problems that time and labor are wasted due to the fact that known diesel engines are started by manually rotating inertial wheels; the diesel engines cannot be started normally when the voltage is abnormal if the diesel engines are started by adopting storage batteries; starting timeliness and safety of the diesel engines cannot be guaranteed easily on emergency occasions where the diesel engines are adopted. According to the multi-starting mode layout structure of the diesel engine, a double-lug flywheel casing is fixed on the rear end face of the engine and provided with a pneumatic motor mounting hole site and a hydraulic motor mounting hole site. A pneumatic motor and a hydraulic motor which are two different starting modes are adopted to serve as starting motors of the diesel engine; when the starting by means of the pneumatic motor fails, the hydraulic motor can be adopted to start the diesel engine, and the multi-starting mode layout structure guarantees that the diesel engine can be started normally in any environment.