Abstract: An intelligent monitoring and warning system for dangerous slope was constructed by using laser radar technology， fiber grating sensing technology， video monitoring and GNNS time synchronization technology. The system integrates photoelectric technology， computer software technology， information processing technology， control technology and communication technology. It consists of a monitoring center， a field monitoring center and four functional modules. The real-time monitoring and alarm of foreign matter intrusion in the monitoring area are realized by laser radar system ，the early warning and alarm of slope rock fall disaster are realized by fiber grating sensor system ，the on-site monitoring and disaster confirmation are realized by high definition day-night conversion monitoring camera，and the time synchronization function module of GNSS can realize the accurate time synchronization within the system. The monitoring center and the field monitoring center system integrate four modules to ensure the collaborative work of each module. Its application can release early warning in real time all day ，improve the efficiency and quality of monitoring ， and achieves the purpose of disaster prevention and reduction.

Key words: laser radar, fiber grating, video surveillance, GNNS, slope monitoring