The invention relates to a building method for a photovoltaic power generation control system, which is applicable to photovoltaic power generation, in particular to the field of analysis on the operating state and energy flow of a photovoltaic power generation system comprising an energy storage unit and an electrical energy transformation unit. The method mainly includes the following steps: defining the states of system parts, utilizing a stepped state association table to reduce the state scale, generating effective state links, then representing the state links in a code wheel coordinatesystem figure or a simple physical model, and meanwhile, establishing control schemes for corresponding states. The building method for the control system has the advantage that the building method can visually, accurately and comprehensively master the operating state of the system and realizes complete and reliable control.