The invention provides an interior spraying device for an outdoor dry type electric reactor. The interior spraying device for the outdoor dry type electric reactor comprises a paint storing barrel with a pump. The pump communicates with a shower nozzle through a flexible pipe, the shower nozzle is fixed to a rotary spraying mechanism, and the rotary spraying mechanism is fixed to a supporting mechanism; the rotary spraying mechanism comprises a fixing rack, a rotary shaft, and a rotary rod, one end of the rotary rod is fixed to the rotary shaft, the other end of the rotary rod is fixed to theshower nozzle, the rotary shaft is fixed to the fixing rack, and a motor for driving the rotary shaft to rotate is arranged on the fixing rack; the supporting mechanism comprises a supporting plate, and an air cylinder used for supporting, pushing and pulling the fixing rack is arranged on the supporting plate. According to the interior spraying device for the outdoor dry type electric reactor, the problems that the workload is large, and the staff is not enough are solved, rotating can be conducted in the spraying process, and spraying work can be effectively conducted.