An auto-adjusting separation mechanism, comprising: a bracket with at least one side arm, a sensor module arranged on the side arm, a rotary shaft arranged at the front end of the bracket; a separation roller set pivotally arranged on the rotary shaft, a sensor wheel arranged to couple with the sensor module, and a torque limiter arranged at the front end of the bracket; wherein, by monitoring the rotation of the sensor wheel with the sensor module, the separating force of the separation roller set is adjustable via a microcontrollers which is capable to adjust the transmission gear set.