Impeller as an important part of the Aero-Engine should have a high machining accuracy and quality. The X-axis slide of Aero-Engine impeller dedicated machining center is taken as the research object, which was turned out by a machine tool factory, and its dynamic characteristics are studied by finite element analysis. The weaker part of the X-axis slide is founded according to the analysis of inherent frequency and modal shape, and as to the weaker part, optimization design scheme is put forward to improve the dynamic characteristics of the X-axis slide. This conclusion provides a certain reference to the future optimized design.