A physiological signal detection device has a battery disposed in the physiological signal detection device, a first input terminal, a second input terminal, and a charging detection terminal A physiological signal detection circuit generates a physiological signal according to a detection result of the first input terminal and the second input terminal A charging control circuit is electrically coupled to the first input terminal, the second input terminal and the charging detection terminal, wherein, when the first input terminal and the second input terminal are coupled to a power supply supplied by a charging device, the charging detection terminal receives a charging indication signal of the charging device and according to the charging indication signal the charging device is enabled so as to charge the battery with the power supply.