The invention relates to a power grid synthetic data index monitoring method and system based on a big data platform, and belongs to the field of the power grid big data platform data monitoring. Themethod is capable of executing the index monitoring analysis to the electricity marketing business core index by using a quartile analytical method through a big data platform module, solving the current problem that 'the electricity marketing business scope is extensive and the exposure of the individual business aspect problem is slow', realizing 'data + business' double driving in a certain degree, and improving the working efficiency of the electricity marketing business.