The utility model relates to the field of delay starting switches, especially to a power delay starting switch which includes an EMI filter circuit, a transformer, a bridge rectifier circuit, a voltage regulator circuit, a Schmitt trigger circuit, an optically coupled bidirectional triode thyristor drive and a bidirectional triode thyristor. The EMI filter circuit is sequentially connected to the bridge rectifier circuit, the voltage regulator circuit, the Schmitt trigger circuit, the optically coupled bidirectional triode thyristor drive and the bidirectional triode thyristor through the transformer, and the EMI filter circuit is connected to the bidirectional triode thyristor. The power delay starting switch is advantageous in that the power switching function is achieved only by a electronic device and is thus free of relays; safe isolation of high and low voltage parts of an electronic system is achieved; and the EMI function is suppressed. Compared with the prior art, the power delay starting switch has the characteristics of small size, low loss, safe isolation and small EMI disturbance, and meets the needs of a variety of practical applications.