Nowadays the deformation monitoring of roof subsidence of mine roadway, tunnel, etc., is one of the indispensable means for engineering security. The existing linear distributed fiber optic monitoring technology is low sensitivity. Based on the distributed optical fiber sensing technology, further research is made on the form of the layout of the fiber. We put the fiber along the longitudinal vertical plane layout of roadway roof into sawtooth shape, build the corresponding calculation model, give the layout parameters and obtain the monitoring accuracy and the measurement range(AV6419). The test results show that when we change the linear layout into sawtooth layout it can not only meet the requirements of large-scale field measurement of distributed information capabilities of distributed optical fiber sensing technology, but also realize the purpose of monitoring the radial deformation of the roadway (such as roof settlement) through the arrangement of axially distributed optical fiber in roadway. Besides, this model’s sensitivity will have a substantial increase, so as to provide a new method and ideas for application and promotion of distributed optical fiber sensing technology based on BOTDR.