In this paper a novel approach is presented for determination of the main components in MgO-Cr refractory material. With the approach, the intensity conversion of fused sample at different dilution ratios can be obtained by establishing the correlation between elements’ intensity and dilution ratio. MgO-Cr refractory material is fused hardly and the dilution ratio requires more than 20 in XRF analysis. Nevertheless, high dilution can reduce the detection sensitivity of low content elements. Using the technology of intensity conversion at different dilution ratio in this paper, a calibration curve was obtained with different dilution ratios. In this method, we obtained a calibration curve successfully and got the satisfactory results for MgO-Cr refractory which was fused well. The new method suggests consistent accuracy and precision with standard method, and it can also simplify the preparation process of samples. The approach shows high sensitivity, good accuracy and precision, meanwhile, it reduces the technical difficulty and labor intensity greatly in analysis method.