Based on the existing results of the momentum envelop for the variable speed control moment gyroscope(VSCMG) cluster, in order to design parameters for the multifunction of attitude control and energy storage, the specificity analysis of the momentum envelop and energy storage under the condition of upper speed limit and lower speed limit of flywheel is firstly proposed. The optimal method of flywheel parameters and skew angle of pyramid configuration is cast as the nonlinear, multi-constrains, and strong coupling single objection optimal problem. The sequential quadratic program method is applied to solve the problem of optimal parameters. Finally, the momentum envelop, based on optimal parameters is calculated, and the results show the effectiveness of the proposed method.