This　paper　investigates　the　complicated　dynamic　behavior　and　power　generation　efficiency　of　the　cantilevered　laminated　composite　piezoelectric　beam　with　the　unilateral　layer　separate.　The　effect　of　the　external　excitation　on　the　voltage　output,　the　impacts　of　the　layered　length　of　composite　layers　and　the　influence　of　the　magnetic　distance　on　the　voltage　output　and　the　effective　frequency　bandwidth　are　examined.　Simultaneously,　the　output　voltage　and　the　effective　frequency　bandwidth　of　the　traditional　cantilevered　laminated　composite　piezoelectric　beam　are　measured　experimentally　to　verify　the　developed　model.　The　amplitude　of　the　harmonic　excitation　is　given　the　certain　value　and　is　not　changed.　Experimental　results　show　that　the　developed　structure　has　lower　natural　frequency,　great　voltage　output　and　great　effective　frequency　bandwidth　when　the　length　of　the　separate　parts　between　composite　layers　is　in　the　range.　For　the　different　layered　lengths　of　the　developed　bistable　piezoelectric　beam,　there　exist　the　optimal　magnetic　distance　and　an　optimal　layered　length,　respectively.　The　power　generation　efficiency　of　the　developed　bistable　piezoelectric　beam　is　better　than　that　of　the　developed　monostable　piezoelectric　beam.　When　the　layered　length　of　the　separate　parts　between　composite　layers　is　optimal,　the　voltage　output　of　the　piezoelectric　beam　has　four　peak　voltages.　In　addition,　the　power　generation　efficiency　of　the　developed　structure　are　superior　to　that　of　the　traditional　one.　The　maximum　peak　voltage　of　this　structure　is　6.73　times　than　that　of　the　traditional　piezoelectric　beam,　and　its　effective　frequency　bandwidth　promotes　8.4　times.