A charging device for a physiological signal transmitter is disclosed. The charging device includes a transmitter placing seat, and a controlling module controlling an operation between the charging device and the physiological signal transmitter in a safe state. When the physiological signal transmitter is at the predetermined position, the locking portion unlocks the operating portion to perform one of driving the second electrical connecting port to move from the first position to the second position to electrically connect to the first electrical connecting port and driving the second electrical connecting port to move from the second position to the first position to electrically disconnect to the first electrical connecting port.