The traditional artificial potential field method (TAPF) is prone to the issue of falling into local minimum. Therefore, threat level is introduced in this paper to construct an improved artificial potential field method with the quadrilateral exclusion strategy (QAPF). By defining threat quadrilaterals, targeted repulsive forces are implemented within a designated range, which addresses the local minimum problem for U-traps. Moreover, Cubic Spline Interpolation is utilized to mitigate abrupt changes in the trajectory. Finally, the axis shift artificial potential field (QCAPF) is implemented to optimize the path selection following obstacle avoidance. The simulation results demonstrate that in comparison to TAPF, QAPF effectively resolves the issue of getting stuck in a U-shaped trap and successfully reaches the target point. The Cubic Spline Interpolation minimizes sharp bends and oscillations in the trajectory. While avoiding local minimum problems, QCAPF optimizes trajectory planning after steering clear of high-threat obstacle areas, selecting a path with fewer high-threat obstacles, and ultimately reaching the target point.