A multi-dimensional power grid data quality evaluation system is designed in this paper to solve issues such as single dimension, incomplete coverage and objectivity in data quality evaluation of power grid dispatching. The evaluation index of data quality is extracted according to the grid model parameters, the grid steady-state data and the grid fault characteristic data. The weight of this system assessment is determined and the comprehensive score is generated all based on the entropy value of the index combined with the subjective weight selection method. The system is deployed in III-area of a real smart grid dispatch control system, and a series of procedure are carried out through the Webservice way. The results show that this designed multi-dimensional power grid data quality evaluation system could provide a more intuitive integrated data assessment and evaluation method for the grid dispatching personnel, so as to ensur e the safe and reliable operation of the grid dispatching system.