The utility model relates to a preassembly fixed switch complete device which comprises a shell body; wherein the interior of the shell body is provided with a switch chamber, a feeder chamber, a meter installing chamber and a maintenance chamber; the switch chamber is arranged on the upper part of the shell body and comprises an upper isolating switch, a vacuum circuit breaker, a current transformer and an inlet wire female header; the feeder chamber is arranged on the lower part of the shell body and comprises a lower isolating switch, a sensor, an outlet wire female header and a bus sleeve; the meter installing chamber is arranged on the left bottom part of the shell body and its interior is provided with a computer control and protection device; the maintenance chamber is arranged on the right part of the shell body, the vacuum circuit breaker is an integrative vacuum circuit breaker, and the computer control and protection device is the preassembly fixed type. Adopting the preassembly fixed type installation, most of connection and installation work is finished in the factory, which has the reliable improvement and the less failure, saves the construction time, reduces the field installation cost, occupies the less land and has the large overhaul space and the convenient maintenance. The shell door on the panel of the switch complete device shell body can play an explosion-proof role and improves the security.