In view of the problem that the torsion of inclinometer casing grooves leads to the deviation of deep horizontal displacement data from the main sliding direction and the underestimation of values in the monitoring of deep excavation high slopes of Pinglu Canal,the torsion effect analysis and correction method research are carried out on the basis of the HD10 section project.By a coordinate projection transformation model,the geometric mapping relationship between measurement components and real deformation is revealed,and a graded correction strategy considering both calculation accuracy and engineering efficiency is proposed.The results show that nonlinear torsion is common in actual inclinometer holes,with a maximum torsion angle of 27.5°.After adopting the proposed graded correction method,the deviation between the displacement vector and the design main sliding direction decreases from 20.2° to 3.6°,effectively eliminating the risk of misjudging the sliding direction.The displacement amplitude at the key sliding surface increases by 3.2%-8.5%,and the deviation rate between the corrected cumulative displacement at the hole top and the surface displacement monitoring value decreases from 12% to 3.5%.The method solves the accuracy bottleneck of displacement vector restoration under complex torsion working conditions and provides reliable data support for the stability evaluation of channel high slopes.