30 8 2022 4 , efficiency of the review are this paper the big data preprocessing method is used to analyze the , data of large⁃scale power grid project and the technical and economic evaluation of power grid planning , and fixed assets investment projects is carried out as well as the data processing work related to the , planning project management information taking guangzhou power supply bureau as an , example an intelligent evaluation and analysis system of investment cost data is developed and , designed which is suitable for the scope of the power supply bureau. It is responsible for the data , analysis reporting and publishing of the industry quota in the numerical experiments show , that the preprocessing method can effectively improve the efficiency of data compression. preprocessing data analysis cost evaluation power grid engineering data intelligent analysis Keywords: ; ; ;