Abstract: The monitoring of ground fissures plays an important role in the prevention and control of the ground fissure hazard. In this paper, BOTDR-based distributed monitoring technology is used to monitor the development process of ground fissures. The principle of distributed optical fiber sensing technology and the distributed monitoring method are introduced. The field monitoring of ground fissures located in Wuxi is studied. The results show that BOTDR-based distributed monitoring technology can be effectively used to the deformation monitoring of ground fissures. Its monitoring accuracy and measuring range can be improved by the fixed-point layout of optical fiber. The monitoring accuracy can reach 0.1mm and the measuring range can raise 30mm. The multiple ground fissures within a certain area can be monitored by the gridded laying of optical fiber. The positioning accuracy of the ground fissure monitoring can be improved by setting up the different lengths between two fixed-points along the same direction.