We propose a physical model of multiple domain nucleation and growth in order to perform the cross-scale simulation on envelope profiles of the domain and the internal structure. The model utilizes two coupled field: a nonconserved envelope vector field of the local macroscopic growth domains and a vector field of the local mesoscopic lamellae directors. The envelope evolution equation includes an envelope profile function, the domain growth and impingement kinetics, the relaxation of the envelope by a surface tension, a lowest-order nonlinear term, a noise term, and a surface diffusion term. The splay, twist and bend deformation and the interaction between lamellae and noise field are considered in the free energy density equation of the lamellar director field. Results of large-scale computer simulation are reported which are compared with experiments.