Abstract: A motion control mechanism of the oil pressure cylinder comprises an oil storing cylinder, a driving rod and a reversible motor. The oil storing cylinder is in communication with the oil pressure cylinder having a piston rod and is provided therein with a piston which is provided at one end thereof with a coupling portion. The driving rod is provided at one end thereof with a connection head engageable with the coupling portion of the piston and is further provided therein axially with a threaded hole engageable with a threaded rod which is fastened at one end thereof with an output shaft of the reversible motor. The piston is actuated by the driving rod to move back and forth within the oil storing cylinder so as to control the motion of the piston rod of the oil pressure cylinder.