Abstract: In order to study the effect on deformation strength of coal fly ash produced by reinforcement layers,moisture content and confining pressure,test is made on the plane strain of ash having different number of reinforcement layers,moisture contents and confining pressures using a py- 10 plane strain gauge,with an aim to defining the law governing the variation of stress in relation to strain and the shear strength of fly ash. Result of test indicates that in case the confining pressure,the stress and strain assume in all cases a linear relationship. Whereas,with the increasing reinforcement layers,decrease of moisture content and increase of confining pressure,the shear strength of fly ash tends to increase to varying degrees. In other instance,with the increase of reinforcement layers and confining pressure,and reduction of moisture content,the fly ash is seen to have a higher structural strength due to effective diminution of deformation.