Abstract: Aiming at the problem of low precision caused by insufficient data and noise interruption,the paper attempts to set up and improve the forecasting model of variable dimension based on fractal theory.Meanwhile,with the monitoring data of slope displacement from the Xiaowan Project,and Curve D1,D2 as the fractal parameter curves of the forecasting model,it tends to predict the displacement by calculating the sub-fractal dimension,and comparing the forecast result with the gray model GM(1,1) and BP neural netw...