This paper aims at predicting the solid-mass flow rate of pulverized coal in dense-phase pneumatic conveying systems. A one-dimensional model was developed based on the proper modification of a dilute-flow model by inserting a two-phase flow multiplier. The relationships between the model parameters (discharge coefficient and pressure ratio parameter) and the hydrodynamic nondimensional numbers (Reynolds and Stokes numbers) were determined, and the fitting coefficients were obtained from calibration tests by using regression analysis. Two methods attached to the model were proposed to predict the solid-mass flow rate, and both can provide satisfactory predictions with acceptable errors. These results indicated the possibility of applying a venturi device to measure the solid-mass flow rate at high-pressure and dense-phase conditions.