Abstract: With the rapid development of micro-propulsion technology,it is increasingly difficult to test and calibrate the micro-thrust. According to the principle of differential acceleration of superconducting gravity gradiometer,we propose a designto precisely test micro-Newton thruster based on high temperature superconducting and SQUID detecting technology,with range 10mN and accuracy and frequency band 4. Transfer function of propeller thrust to output differential current is deduced based on kinetic equations of test masses and conservation equations of magnetic flux of superconducting loop. Some important noises are analyzed. Lastly,it is suitable for testing microthrust in addition to considerable potential of improving accuracy.