The dynamic variables and static variables are weakly coupled in dynamic optimal power flow problem. In this paper， the root cause of decomposed primal-dual interior point method is analyzed. The decoupling strategy is applied to solve linear equations in predictor-corrector interior point method， and a decomposed predictor-corrector interior point method is proposed. Moreover， considering the feature of constant term in linear equation， a synchronous iteration strategy for grouped variables is also proposed to predict and correct dynamic variables and static variables synchronously. By taking advantage of decoupling strategy and synchronous iteration strategy， the efficiency of solving dynamic optimal power flow problem is improved. Simulations on standard systems verify the effectiveness of the proposed method.