Expressway active road occupation early warning system based on wireless network

The invention discloses an expressway active road occupation early warning system based on a wireless network, belongs to the field of optics, and aims to solve the problem that an existing traffic cone is insufficient in active early warning capability. The system comprises a sentry node and an alarm node, the alarm node is arranged on a construction road section, and the sentry node is arranged on a normal traffic road section behind the construction road section and is D away from the alarm node; the sentry nodes are arranged on the two sides of a road of a normal traffic road section and used for detecting vehicles on the road surface, and when it is detected that a vehicle enters, the sentry nodes send vehicle entering signals to the alarm node in a wireless communication mode; the alarm node is used for receiving the vehicle driving-in signal sent by the sentry node, giving an on-site alarm to an on-site constructor and reminding the on-site constructor that a vehicle is driven in behind; and the alarm