Abstract: In order to study dynamic features of height adjusting system during the cutting drum height adjusting process of coal shearer and to realize control of the C utting drum position of coal shearer,a mechanical principle theory was applied to establish crank shaper mechanism movement model of height adjusting mechanic system. A Matlab software was applied to the simulation. The simulation results showed that during the uniform moving process of height adjustment hydraulic system,a ranging ar m would have impact force to connecting pin shaft. According to a long stroke of height adjusting cylinder in height adjustment hydraulic system,a valve controlled asymmet ric cylinder model suitable to large displacement piston was established. The analysis results showed that in consideration on effective volume variation of height adjustme nt cylinder,the valve controlled asymmetric cylinder model would be nonlinear. Finally,a AMESim software was applied to establish a mechanic and hydraulic collaborated si mulation model of height adjusting system for coal shearer. A comparison was made on the swing angle actual value and ranging arm given value. The results showed that in consideration on the cutting resistance of cutting drum and gravity comprehensive role of cutting drum and ranging arm,an angle displacement feedback of the ranging a rm and height adjustment control model controlled by electric and hydraulic directional valve could be applied to realize position control of coal shearer.