Fuente: Wipo "IOT" The present invention relates to a system for avoiding simultaneous connection of an Internet of things (IoT) device group, in which a simultaneous connection situation is avoided to prevent that a connection limit capable of being allowed by a wired/wireless gateway or a wireless repeater is exceeded when a plurality of clustered IoT devices to which regular power are not supplied so that limited power resources of the IoT devices are efficiently operated and information is stably transferred to a server through the wired/wireless gateway or the wireless repeater, and a method thereof. According to the present invention, the method comprises the following steps of: allowing the IoT device to monitor regular power supplied thereto (S10); when it is detected that the constant power is cut off as a monitor result, allowing the IoT device to recognize the cut-off of the regular power and generate a random number (S20); allowing an operation unit to use a connection sequence number based on the generated random number to determine the wakeup time of the corresponding IoT device (S30); switching each IoT device of an IoT device group to a sleep mode (S40); allowing the operation unit of the corresponding IoT device to perform wake-up in accordance with the wake-up time (S50); and allowing the IoT device of the corresponding connection sequence to use the wake-up time to perform communication connection to the wired/wireless gateway or the wireless repeater and transmit data (S60). COPYRIGHT KIPO 2021