Simplified calculation formula often appears in the grade calculation of sedimentary ilmenite, ignoring factors such as TiO2 content in ilmenite minerals and the proportion of ilmenite in titanium phase, which leads to deviation in the calculation data of ilmenite grade and affects the calculation of ilmenite reserves and the economic calculation of the project. In order to reduce the error in the calculation of ilmenite grade, based on the exploration data of the ilmenite projects in Mozambique and Malawi, this paper discusses the actual content of TiO2 in the ilmenite mineral and the significance of the proportion of ilmenite in the titanium phase analysis, and correctly uses the calculation formula of ilmenite grade to make the calculation of the grade of sedimentary ilmenite closer to the actual content, It provides important support for improving the accuracy of ilmenite placer resource reserves and project economic estimation.