Abstract: In order to effectually solve the electromagnetic field problems in the complex multi branch domains, this paper presents the fast convergence pattern on many spaces for decomposition projective method (DPM) with optimal parameters. The design and formula of the optimal parameters are also given. Practical application shows that the convergence rate is quicker than DPM. The iterative number of the fast convergence pattern with optimal parameters decreases greatly-about one third of that of DPM, and the efficienty is raised.

Key words: decomposition projective method, projective operator, multi-branch domain