A new method, triboelectricity and ultrasonic, for the soot mass flow measurement is developed. The direct rod-shaped sensor is used to measuring the triboelectricity charge and the ring sensor is used to measuring the electrostatic induction charge. The pure-triboelectricity can be figured out and the pure-triboelectricity is eliminated the influence of the electrostatic induction. Through the numerical simulation, the proportion between the electrostatic induction charge and the electrostatic induction charge is presented. The gas flowrate is measured by the ultrasonic. The soot mass flow can be figured out through the pure-triboelectricity and the gas velocity. Additionally, the sample calibration equipment based on the pure-triboelectricity and ultrasonic method is also introduced. Experimental results show the method can on-line measure the soot mass flow.