The purpose of this study was to evaluate the reliability of 6-axis model surgery simulator (6AMSS) for orthognathic surgery. A rectangular parallelepiped plastic block was assembled to model-mounting plate of 6AMSS. Left-right (X), anterior-posterior (Y), up-down (Z) translation and pitching (${phi}X$), rolling (${phi}Y$) and yawing (${phi}Z$) rotation was planned and performed using 6AMSS. The actual translation and rotation were measured with dial gauge and precisional protractor, respectively. Comparison between the planned and actual movements of plastic block for each variable were made using paired t- test. Statistical analysis for X, Y, Z, ${phi}X$, ${phi}Y$ and ${phi}Z$ movement have shown no significant differences between planned and actual movement (P > 0.05). This indicate that model surgery performed with the aid of the 6AMSS is accurate in 3D translation and rotation. The 6AMSS is practically useful for accurate fabrication of surgical splint for orthognathic surgery.