The utility model provides a colliery is fan monitored control system in pit, include: the first mechanism of fan in the pit, the second is fan mechanism in the pit, substation explosion -proof case in the pit, optic fibre changes the ethernet device, looped netowrk transmission platform, aboveground data monitoring device, the first mechanism of fan in the pit, the second is fan mechanism in the pit, substation explosion -proof case in the pit, optic fibre changes the ethernet device and installs in the pit, in the pit the substation explosion -proof case pass through the RS485 bus respectively with the first mechanism of fan in the pit, second fan mechanism in the pit is connected, the substation explosion -proof case passes through optic fibre and optic fibre commentaries on classics ethernet device and links to each other in the pit, optic fibre commentaries on classics ethernet device passes through the ethernet with looped netowrk transmission platform and links to each other, looped netowrk transmission platform passes through the ethernet and links to each other at aboveground data monitoring device with installing. The simple structure of this system, man -machine interface is friendly, and convenient operation can realize tunneling control of local ventilation system security and monitoring in the pit to the colliery, improves the production of coal mine safety, reduces the colliery emergence probability of gas explosion accident in the pit.