Abstract: The issue of product deformation during the upper jaw production in Metal Power Injection?Moulding?(MIM) technology stemmed from poor binding material adhesion and excessive shear heat generation, leading to uneven metal powder distribution. To address this problem, a series of melt index experiments were conducted using three different materials with varying powder content. These experiments assessed fluidity and coupling characteristics. Utilizing?the Taguchi method, extreme deviation analysis, and analysis of variance, the?optimization?of three critical process parameters—gate area,?mould?temperature, and injection temperature—was pursued. The objective was to investigate how these process parameters interacted and affected shear stress. Ultimately, the most effective combination was determined to be a powder loading of 62.5 vol% alongside the following process parameters: a gate area of 23.984 cm2, a?mould?temperature of 69.854 ℃, and an injection temperature of 194.323 ℃. Validation analysis using Moldex 3D software confirmed that this set of conditions resulted in the lowest shear stress within the product and the highest level of powder uniformity. Consequently, this?optimized process configuration successfully alleviated the deformation issue in the final product.