Impulse measurement scheme for a nitrous oxide (N2O) monopropellant micro-thruster was presented.The experiment results were used to fit the relationship between the steady thrust and the pressure.Dynamic pressure was utilized to calculate the thrust and impulse.Two different micro-thrusters with catalytic bed of φ 8mm×35mm and φ 10mm×25mm were fabricated and experimented.The influence of the mass flow on the specific impulse performance was studied.The relationship between the steady thrust and the pressure in different mass flow rates was obtained.Experiment strategy and analysis result can provide some reference for accurate control of the micro-thruster impulse.