In order to improve the automatizaion and informatization level of tunnel construction ventilation system in China, a monitoring system of tunnel construction ventilation based on industrial Ethernet (IE) is proposed. The monitoring system is composed of industrial personal computer (IPC), 1200 series programmable logical computer (PLC) and relative modules and sensors. The monitoring program of IPC is written by software WinCC, which can realize the realtime monitoring of tunnel construction environment and working parameters. The neural network algorithm is used to study the field data, which can obtain the control law of output frequency of the transducer. The industrial Ethernet between 1200PLC and IPC is established by Ethernet cable, optical fiber and wireless LAN, which can realize the sharing of system environment parameters and work parameters. The system is debugged and tested in the construction ventilation project of Tianmushan Tunnel. The results show that: 1) The 1200PLC can collect the data of multiple sensors smoothly by using 485 cable and Modbus protocol under the construction environment of tunnel face. 2) The technology of WIFI could be used to realize the stable transmission of information between the two ends of the lining formwork trolley. 3) The artificial neural network could be used to realize the nonlinear representation between the environment parameters and the fan frequency.