The invention discloses a power system power flow calculation data conversion method. At present, power grid data information is processed manually, as a result, the technical problems of miscellaneous sorting process and high possibility of making mistakes caused by a large quantity of the information of a large-scale alternating current power grid and diverse and varying wiring modes of the power grid can be brought out, while, with the power system power flow calculation data conversion method of the invention adopted, the above problems can be solved. According to the embodiments of the invention, the method includes the following steps that: high-voltage bus-bar information is sorted out from power flow calculation data, a corresponding relation table between substation fields and high-voltage bus-bar fields is created according to substation information; high-voltage power transformer information and high-voltage line information are sorted out from the power flow calculation data according to the relation table, and the connection relation of a high-voltage power transformer and a high-voltage bus-bar and the connection relation of a high-voltage line and the high-voltage bus-bar are determined; and the substation information, the high-voltage power transformer information, the high-voltage bus-bar information and the high-voltage line information are exported as an XML file used for direct-current distribution calculation.