The invention discloses an agricultural machinery running mechanism. A running wheel train is mounted under an operating underframe; an engine support is mounted on the operating underframe; the engine support is used for supporting an engine; a clutch is connected with a power wheel; a wheel belt of the power wheel is connected with a driving wheel assembly; the driving wheel assembly is connected with the running wheel train; through the wheel belt, the power output by the engine is provided for the running wheel train; and a running clutch tensioning wheel system is also mounted on a frameabove the operating underframe and used for tensioning the wheel belt driven by the clutch. The agricultural machinery running mechanism has the advantageous effects of strong passing performance, large loading force, small turning radius, low noise and no damage to asphalt road surface.