The current method of micro-force generated for sensor calibration is scarcity and complexity. In the paper we propose a mechanism based on flexible hinges for micro-force, illustrate its working principle and establish the mechanical model. By theoretical analysis the analytical expression of the force reduction multiplier is derived. After initializing some parameters, the result shows that this mechanism can produce the large range and high resolution force of µN. The force can be applied in calibration of micro-force sensor.