The invention relates to the field of computer technology, and particularly to a power system power flow calculation method based on cloud computing technology. The method includes the following steps: A) importing power system data, and dividing a power system into multiple areas; B) obtaining multiple sub-grids by dividing according to voltage levels; C) taking power flow calculation of each sub-grid in turn as a task; D) verifying sub-grids in the area, entering a step E if verification is successful, and otherwise, changing a power flow calculation method, and returning to the step C; andE) carrying out joint solving verification on all the areas, completing power flow calculation of the power system if verification is successful, and changing a power flow calculation method to re-carry out power flow calculation if verification is unsuccessful. Substantial effects of the power system power flow calculation method are that power flow calculation of the power grids of all the areascan be carried out in parallel through a manner of cloud computing, and efficiency of power flow calculation is greatly improved.