Abstract: In view of problems of less monitoring points, low resolution, long measurement cycle of existing slope monitoring method, a monitoring method of slope based on fringe projection and two-dimensional principal component analysis was proposed in order to real-timely monitor settlement of slope and effectively restrain false alarm. Firstly, the method uses triple-frequency color fringe projection profilometry to obtain height information of observed slope quickly and accurately. Then it uses two-dimensional principal component analysis to analyze the height information and simplify computation amount. Finally, it adopts Euclidean distance corresponding to the measured slope position of different times to judge whether the slope false alarm occurs. The experiment results show that the monitoring method can effectively monitor false alarm of slope, and has a good performance of real-time and robustness.