A suction casting experiment was conducted on Zr₅₅Cu₃₀Al₁₀Ni₅ (at%) amorphous alloy. Using ProCAST software, numerical simulations were performed to analyze the filling and solidification processes. The velocity field during the filling process and the temperature field during the solidification process of the alloy melt under different process parameters were obtained. Based on the simulation results, a Zr-based amorphous alloy micro-gear was prepared via casting. The results indicate that increasing the suction casting temperature enhances the fluidity of alloy melt but induces unstable flow rate during filling, which is detrimental to complete filling. Zr-based amorphous micro-gears with a module of 0.6 mm, a tooth top diameter of 8 mm, and 10 teeth were prepared through the suction casting. X-ray diffraction and differential scanning calorimetry analyses confirm that the fabricated micro-gear exhibits characteristic amorphous structural features, demonstrating well-defined geometrical contours and satisfactory forming completeness.