A new displacement conversion method was constructed displacement function model by uniform cross-section cantilever and employed the Moore-Penrose generalized inverse to solve the matrix equation for the displacement. The slope displacement curve was obtain, where inclinometer tube was installed. This displacement conversion method is proved to be accurate through FEM simulation and indoor proportional model experiment. This method is also successfully applied in real-time monitoring of Diaoshuiyan slope in combination with FEM strength reduction technique, which further verifies its effectiveness.