Abstract: In this work, the micromagnetic simulation confirms that it is feasible to realize deterministic field-free switching by driving topological insulator/wedge ferromagnetic heterostructure with ultra-low current density.In addition, we studied the effects of wedge-shaped ferromagnetic layer size, interfacial Dzyaloshinskii-Moriya Interaction (DMI), field-like torque and tilted perpendicular magnetic anisotropy off-pole angle on spin-orbit torque field-free switching.Through comprehensive optimization, the minimum critical switching current density of the topological insulator (BiSb)/wedge - shaped ferromagnetic heterostructure can be reduced to 9.0×10⁶ A/cm², which is 1 ~2 orders of magnitude lower than that of the traditional heavy metal/ferromagnetic structure.This research is of great significance for promoting the industrial application of low-power spin-orbit torque magnetic random-access memory.