An embedded system is disclosed. The embedded system is used for preventing a processing machine from an abnormal phenomenon when at least one processing parameter setting value is inputted into the processing machine. The embedded system is electrically connected to the processing machine, and the processing machine comprises an input interface, a first storing medium, a first controller and a stepper motor. The embedded system comprises a second storing medium and a second controller. The second controller captures the a processing parameter setting value inputted and compares it with a security range, so as to determine whether the processing machine is able to perform process for a workpiece. When the second controller determines that the processing machine is not able to perform process for the workpiece, a stop signal is generated and transmitted to the processing machine to stop performing process for the workpiece.