The invented physiological signal sensing device comprises a power source control circuit, a voltage stabilizing circuit, a control circuit, an isolation circuit, and a signal processing circuit. The power source control circuit is connected with a power source. The voltage stabilizing circuit is connected with the power source control circuit. The control circuit is connected with the voltage stabilizing circuit and the signal processing circuit. The isolation circuit is connected with the power source control circuit, the control circuit, and the signal processing circuit and has at least two detection ends. When in use, two detection ends are connected with a physiological impedance therebetween. When an impedance value of the physiological impedance is within an impedance range, the power source control circuit triggers the voltage stabilizing circuit through a trigger path and supplies the power to the voltage stabilizing circuit through a power supply path and the voltage stabilizing circuit supplies power to the control circuit. The trigger path and the power supply path are connected in parallel.本發明的生理訊號檢測裝置包括一電源控制電路、一穩壓電路、一控制電路、一隔離電路及一訊號處理電路。電源控制電路連接一電源。穩壓電路連接電源控制電路。控制電路連接穩壓電路與訊號處理電路。隔離電路連接電源控制電路、控制電路及訊號處理電路,且具有至少兩偵測端。使用時,兩偵測端之間連接一生理阻抗。在生理阻抗的一阻抗值在一阻抗範圍內時,電源控制電路藉由一觸發路徑觸發穩壓電路,且藉由一供電路徑供電至穩壓電路,穩壓電路供電至控制電路。觸發路徑與供電路徑是並聯連接。S11-S27‧‧‧步驟
