A power tool, comprising: a power supply device; a control processing device electrically connected to the power supply device and comprising a first switch signal output pin, a second switch signal output pin, a third switch signal output pin, and an examination signal input pin, wherein a first switch signal, a second switch signal, and a third switch signal are respectively outputted from the control processing device by the first switch signal output pin, the second switch signal output pin, and the third switch signal output pin; a safety control circuit module comprising a first switch control circuit electrically connected to the first switch signal output pin; a second switch control circuit electrically connected to the second switch signal output pin and the first switch control circuit; a third switch control circuit electrically connected to the third switch signal output pin and the second switch control circuit; a first resistor electrically connected to the power supply device; and a first diode electrically connected to the examination signal input pin and the first resistor; and a power output device comprising: a first power connection terminal electrically connected to the first switch control circuit, the first diode, and the second switch control circuit; and a second power connection terminal electrically connected to the third switch control circuit; characterized in that the first switch control circuit comprises a first driving circuit and a first switch unit; the second switch control circuit comprises a second driving circuit and a second switch unit; the third switch control circuit comprises a third driving circuit and a third switch unit; when the first switch signal, the second switch signal, and the third switch signal are not outputted by the control processing device through the first switch signal output pin, the second switch signal output pin, and the third switch signal output pin, but the second switch unit or the third switch unit is turned on, an abnormal signal having an electric potential lower than the examination signal is received by the examination signal input pin. a power supply device; a control processing device electrically connected to the power supply device and comprising a first switch signal output pin, a second switch signal output pin, a third switch signal output pin, and an examination signal input pin, wherein a first switch signal, a second switch signal, and a third switch signal are respectively outputted from the control processing device by the first switch signal output pin, the second switch signal output pin, and the third switch signal output pin; a safety control circuit module comprising a first switch control circuit electrically connected to the first switch signal output pin; a second switch control circuit electrically connected to the second switch signal output pin and the first switch control circuit; a third switch control circuit electrically connected to the third switch signal output pin and the second switch control circuit; a first resistor electrically connected to the power supply device; and a first diode electrically connected to the examination signal input pin and the first resistor; and a power output device comprising: a first power connection terminal electrically connected to the first switch control circuit, the first diode, and the second switch control circuit; and a second power connection terminal electrically connected to the third switch control circuit; characterized in that the first switch control circuit comprises a first driving circuit and a first switch unit; the second switch control circuit comprises a second driving circuit and a second switch unit; the third switch control circuit comprises a third driving circuit and a third switch unit; when the first switch signal, the second switch signal, and the third switch signal are not outputted by the control processing device through the first switch signal output pin, the second switch signal output pin, and the third switch signal output pin, but the second switch unit or the third switch unit is turned on, an abnormal signal having an electric potential lower than the examination signal is received by the examination signal input pin. a first power connection terminal electrically connected to the first switch control circuit, the first diode, and the second switch control circuit; and a second power connection terminal electrically connected to the third switch control circuit; characterized in that the first switch control circuit comprises a first driving circuit and a first switch unit; the second switch control circuit comprises a second driving circuit and a second switch unit; the third switch control circuit comprises a third driving circuit and a third switch unit; when the first switch signal, the second switch signal, and the third switch signal are not outputted by the control processing device through the first switch signal output pin, the second switch signal output pin, and the third switch signal output pin, but the second switch unit or the third switch unit is turned on, an abnormal signal having an electric potential lower than the examination signal is received by the examination signal input pin.