The utility model relates to a main air -cooled power switch control device and air -cooled control system of becoming wherein, mainly becomes air -cooled power switch control device, including the translation unit who connects current power supply, reserve power supply, still include an on -off control unit, a delay control unit, the 2nd on -off control unit, the 2nd delay control unit and bilateral control unit, the utility model discloses two switching of power's reliability is improved and is optimized the warning signal when causing the coil broken string with electricity to relay coil islong -term. Based on the utility model discloses, in actual application, can realize two way power -ons and cross change over switch and select to regard as main power source wantonly all the way that another way power is as stand -by power supply. Simultaneously, the main power source failover is not having the inspection to handle under the circumstances of main power source trouble, not automatic return main power source (hauling oneself willingly into not runback) to the stand -by power supply after to avoid putting into once more the trouble power, repeated switching.