The interaction between intense laser and plasma can produce various parametric instability processes and nonlinear effects. In this paper, the nonlinear equation satisfied by the transverse field envelope is derived by Karpman method, and the solitary wave solution is obtained in one-dimensional case. It is found that the half width of the solitary wave is inversely proportional to the amplitude of the laser beam. The influence of various parameters in magnetized plasma on the half width of the solitary wave is analyzed. The results show that for the case of right-hand circularly polarized laser, the half width of soliton decreases with the increase of electron number density, and increases with the increase of magnetic field intensity. In the case of left-hand circularly polarized laser, the half width of soliton increases with the increase of electron number density, and decreases with the increase of magnetic field intensity.