The invention discloses a server cabinet with an air conditioner. The server cabinet with the air conditioner is mainly formed by a server cabinet body, a server, an evaporator, an electronic expansion valve, an outdoor refrigeration device, a blower fan, a temperature measuring device, an air channel, a water pan, a water pipe, wire slots and a circuit control system. The cold air outside the cabinet enters the cabinet from a cabinet front door and realizes heat exchange with the server; after temperature rise, the air enters a back-side air return duct; and hot air rises and carries out heat exchange with the evaporator to form cold air, which is output through the blower fan, thereby finishing cooling of the server. According to the cabinet, by arranging the evaporator slantly at the upper portion of the cabinet, the height of the air-conditioning system is allowed to be less than 300 mm, that is, the height of the cabinet is less than 2300 mm, thereby meeting housing metal plate dimension design and house height design, not occupying standard cabinet space, and enabling the space utilization rate of the cabinet to be maximum; and two and more than two devices can serve as standby to each other, thereby ensuring absolutely-safe high-density heat dissipation requirements, and enabling the server to work safely and reliably.