Abstract: In view of the problem of hard to quantitatively calculate the history matching precision of reservoir numerical simulation at present, this paper presents four error characteristic values of history matching by in?depth analysis of the history matching errors, which can be used to quantitatively describe the characteristics of the whole history matching and display error distributions at each time period, and then a quantitative matched standard is established to evaluate the history matching quality of the reservoir indexes and single well indexes. Based on this standard, a new method for calculating history matching precision of indexes of reservoir and single well is proposed to quantitatively represent the precision of the history matching and evaluate the reliability of models. The case study indicates the practicability of the method