In recent years

the mountain tunnel collapse accidents occur frequently in China

which results in heavy casualties and huge property damage. Hence

the real-time field monitoring of surrounding rock stability and the early safety warning have become one of the key issues in current mountain tunnel constructions. Firstly

this paper clarified all the relating concepts of the remote online monitoring technology

including its signal collection

transmission and background processing principle

focus control system（FCS） and general packet radio service（GPRS）. Then

a new type of tunnel remote telemetry system was proposed. The system adopted the wired and wireless networking schemes in the tunnels

including the signal collection and transmission subsystem

the management analysis subsystem and the remote receiving subsystem. Finally

the system was applied to Dashizi tunnel with the high-risk collapse

the longest road tunnel in Ningbo. All-weather real-time high-frequency monitoring was recorded

including the deformation of surrounding rock

the stress of bolts

and the shotcrete stress between surrounding rock and steel arch. In addition

server + client mode was employed to achieve a high-speed transmission of remote data and multi-unit real-time monitoring. The obtained time-history curves（i.e.

deformation

stress and pressure） were analyzed. It indicates that the deformation of surrounding rock of Dashizi tunnel shows a change of the step-like fluctuation and exhibits a mutation after blasting excavation. Meanwhile

it is found that the deformation of surrounding rock and the pressure of the shotcrete layer are greatly affected by the tunnel excavation disturbance. However

the overall trend of change basically undergoes rapid change at the early stage

a slow change at the middle stage and the gradual stability at the late stage. Through the remote online monitoring of the tunnel for nearly one year

it shows that the technology can realize the long-range telemetry and unattended warning of the stability of underground engineering surrounding rock

which has great application prospect.