Abstract: Density is an important indicator in production and sales of crude oil. According to the density of oil products, crude oil can be divided into light oil, medium-Ⅰ oil, medium-Ⅱ oil and heavy oil, and the prices of different oils vary greatly.Through the density testing of various oil products at different mix ratio and with reference to the calculation model of theviscosity, freezing point and yield value of mixed crude oil, calculation model of crude oil density was put forward based onthe massive experimental data. Comparing the measured density with the predicted density of the model, it is found that themaximum error is 0.001 584 g/cm³, and the average error is less than 0.000 6 g/cm³, which meets the error standard of thenational density test. Therefore, the prediction result of the model is relatively accurate and could provide a reference for onsiteblending.