The telescopic cylinder of the heavy lorry crane is an elongated member.During normal operation,it mainly bears axial pressure load and buckling will occur when the axial pressure load is equal to the critical pressure load.As the telescopic cylinder is fixed on the telescopic boom and it deforms with the deformation of the telescopic boom,so the telescopic cylinder will generate a relative offset.As the result,the buckling is easier to occur and the crane 〖BF〗can’t 〖BFQ〗work as usual.The buckling analysis was carried out on the telescopic cylinder of the heavy lorry crane based on ANSYS Workbench and then the influence of deformation on the stability was determined.Finally,some measures were offered to improve the stability of the telescopic cylinder.It provides a reference for engineering designers.