<p>We proposed a microscopic mechanical model for the effective elastic modulus of resin mineral composites based on the Mori-Tanaka method and equivalent inclusion theory to predict the elastic modulus of these materials. The model-predicted values were compared with the experimental results. The results show that when the resin dosage is lower than 10 wt%, the predicted value is lower than the measured value, and the decrease in porosity is obvious; when the resin dosage is higher than 10 wt%, the predicted value is higher than the measured value, the maximum error is 7.95%, and the decrease of porosity is not obvious. The model can predict the trend of the change of elastic modulus. The elastic modulus of resin mineral composites decreases with the increase of porosity. Therefore, the resin dosage should be controlled within 10 wt% when designing the experiments, which provides a guiding direction for the mechanical properties of resin mineral composites to be improved afterward.</p>