An evaluation index system, method and time-spatial extrapolation for smart level of regional grid are presented in this paper. The system employs an index named critical technology adaptability to evaluate the supporting role of key technology to the development of regional grid, and the critical technology adaptability is calculated based on technology readiness level (TRL). Evaluation results are obtained by the combined ordering relation and variation coefficient method. The obtained results are fast predicted in time dimension based on Logistic model, and extrapolated in spatial dimension based on partial least squares analysis for some regions without enough bottom data. The effectiveness of the proposed method and feasibility of the time-spatial exploration are verifid by application instanses of two provincial power grids.