On the base of ANSYS/LS-DYNA, the finite element model of single-path incremental forming of conical part was constructed.It was researched that the influencing factors of max-diameter of area with stable thickness after thinning band appeared in singlepath incremental forming conical part process by using numerical simulation and experiments methods. The results show that the max-diameter of area with stable thickness increases almost linearly with the increasing of forming angle and the diameter of conical part; and the spindle feed step and blank thickness have little effect on the maxdiameter of area with stable thickness. So, a conical part with uniform wall thickness can be gotten by enlarging blank size.