This　paper　presents　the　analysis　on　the　nonlinear　dynamics　of　a　deploying　orthotropic　composite　laminated　cantilever　rectangular　plate　subjected　to　the　aerodynamic　pressures　and　the　in-plane　harmonic　excitation.　The　third-order　nonlinear　piston　theory　is　employed　to　model　the　transverse　air　pressures.　Based　on　Reddy＇s　third-order　shear　deformation　plate　theory　and　Hamilton＇s　principle,　the　nonlinear　governing　equations　of　motion　are　derived　for　the　deploying　composite　laminated　cantilever　rectangular　plate.　The　Galerkin　method　is　utilized　to　discretize　the　partial　differential　governing　equations　to　a　two-degree-of-freedom　nonlinear　system.　The　two-degree-of-freedom　nonlinear　system　is　numerically　studied　to　analyze　the　stability　and　nonlinear　vibrations　of　the　deploying　composite　laminated　cantilever　rectangular　plate　with　the　change　of　the　realistic　parameters.　The　influences　of　different　parameters　on　the　stability　of　the　deploying　composite　laminated　cantilever　rectangular　plate　are　analyzed.　The　numerical　results　show　that　the　deploying　velocity　and　damping　coefficient　have　great　effects　on　the　amplitudes　of　the　nonlinear　vibrations,　which　may　lead　to　the　jumping　phenomenon　of　the　amplitudes　for　first-order　and　second-order　modes.　The　increase　of　the　damping　coefficient　can　suppress　the　increase　of　the　amplitudes　of　the　nonlinear　vibration.