In order to study the effects of water stress ongrowth，yield，key quality and related physiological indexes offoragebarley，split plot experiment was conducted using drought stress time as the mainfactor(10，20 and 30d)and therewatering level(W1，W2 andW3)as the secondary factor while weighting the pots to control water amount in 2017 and2018.The changes in plantheight，earlength，growthperiod，yield of per plant and composition factors，key qualityindicators and chlorophyll content of forage barley weredetermined.The results showed that the drought stresstime(T)significantly decreased the variousindicators.The measured values of indicators showed as T1>T2>T3.Compared withT1，the plant heights of T2 and T3 were reduced by 10.87 and 16.26cm，and the growth period was 5.12 and 14.00 dearlier；thegrain number perspike，1 000 -grain weight and yield per plant were significantly reduced by 37.77% and67.06%，15.68%and30.62%，28.72% and 69.09%respectively；the grain protein content was increased by 4.33% and 10.16%significantly；the grain starch and plumpness were reduced by 5.65% and22.78%，by 12.83% and 18.95% significantly.During thesame stress period，all the measured indicators decreased with the reduction of rewatering levels in different degrees exceptfor proteincontent，the measured values of the indicators were all expressed asW1>W2>W3.Compared withW1，thereduction of W3 was particularly obvious under the T2 and T3 stress time.By measuring the chlorophyll content of barleyleaves，it was found that W1 and W2 treatments had significant compensatory effects after rewatering under T1 and T2 stressperiods，while W3 treatments under T1 and T2 stress periods and all of rewatering treatments under T3 stress periods did notproduce significant compensatoryeffects.The compensation effects of forage barley drought rehydration should be aware thatdrought stress period should not exceed 20days，and the rehydration amount after drought should not be lower than 55% to60% of the maximum soil water holdingcapacity.