The invention relates to an optimal 
power flow calculation method considering discrete and 
sequential decision variables for a large-scale power distribution network. The optimal 
power flow calculation method is characterized by comprising the following steps of building a 
mathematical model of a complicated three-phase unbalanced power distribution network, carrying out complicated optimal 
power flow calculation 
decomposition, and carrying out a simplification process on network loss calculation of the three-phase unbalance power distribution network. By the optimal power flow calculation method, the complicated 
optimization problem can be decomposed into an integral 
linear programming primal problem and a non-linear feasible subproblem, 
decision making optimization and 
system security constraint are organically combined by using mutually-iterated calculation decisions, the optimal power flow is embedded to a 
decision process, and meanwhile, rapid calculation on asymmetric power flows at a large scale is achieved. The optimal power flow calculation method is suitably used for three-phase unbalance power flow calculation, looped 
network structure, bidirectional power flows, real-time decision of discrete and 
sequential decision and optimal power flow, and has the advantages of scientific reasonableness, high adaptability, operation accuracy, high speed and the like.