The invention discloses a power frequency and variable frequency operation switching control device for three working air blowers and two standby air blowers. The power frequency and variable frequency operation switching control device comprises a switching control cabinet, an air molded case circuit breaker, an AC contactor, an intermediate relay, a change-over switch and a signal indicator light, wherein the air molded case circuit breaker, the AC contactor and the intermediate relay all are arranged in the switching control cabinet; the change-over switch and the signal indicator light are arranged on the surface of the switching control cabinet; the air molded case circuit breaker is interconnected with the AC contactor to form a main loop of the control device; and the intermediate relay, the change-over switch and the signal indicator light are mutually connected to the main loop to form a control loop of the main loop. The switching control device is added for a variable frequency and power frequency control power supply, so that variable frequency switching operation of the standby air blowers can be achieved when the working air blowers are in a failure or are repaired; the control requirements of different occasions are met; meanwhile, the equipment investment is reduced; and the speed adjusting function and the energy saving effect of each standby air blower are ensured.