A method of diagnosis and analysis for a regional power grid based on the interval type-2 fuzzy sets and entropy weighting is proposed. First, with a comprehensive consideration of multi-dimensional, multi-influencing factors, independence and operability of the index system, a hierarchical index system for power grid development diagnosis and evaluation is proposed from five perspectives: power grid development speed, scale, safety, efficiency, and benefits. An index normalized scoring method for the index system is proposed. Also, a weighting method is proposed based on the interval type-2 fuzzy sets and entropy weighting. This method can better characterize the fuzzy factors in the process of index weighting. Finally, an empirical analysis is carried out based on the actual data from the Heilongjiang Power Grid. The development of the Heilongjiang Power Grid is evaluated. The results indicate that the overall development of the Heilongjiang Power Grid is good, but still needs to be improved in terms of grid-source coordination, grid-load coordination, grid equipment level, and business operational status. This work is supported by the Chinese Postdoctoral Science Foundation (No. 2018M640127).