MFQ1 dual power conversion switch is a (or several) conversion switch apparatus and other necessary electrical appliances, used to detect a power circuit and to switch one or more load circuits from one power to another. When the common power supply is normal and the function key is placed in the automatic gear, the standby circuit breaker is divided and the common circuit breaker is closed to protect the common power supply from switching on the load. When a common or three phase voltage is interrupted by a common power supply, the ATS converts the load from the common power supply to the standby power supply (when the standby power has a normal voltage), and the standby power is converted to the common power supply when the common power supply is restored to normal.