The significance of the effects of fused deposition modeling (FDM) process parameters (nozzle temperature, platform temperature, printing speed and layer thickness) on the mechanical properties (tensile strength, Young's modulus, breaking elongation) and surface roughness of polyether ether ketone (PEEK) specimens was investigated by designing a four- factor, four- level orthogonal design of experiments. And the optimized process parameter combinations were obtained. The results show that the tensile strength of PEEK samples can reach 86.28 MPa, which is close to the strength of injection-molded PEEK parts, under the conditions of nozzle temperature of 420 ℃, printing speed of 20 mm/s, platform temperature of 140 ℃, and layer thickness of 0.2 mm. Besides, the elastic modulus is 2.14 GPa, the elongation at break is 11.36%, and the surface roughness is 12.17 μm. In addition, the vacuum outgassing performance test of FDM molded PEEK part materials was carried out, and the results show that the total mass loss (TML) is 0.72% and the collected volatile condensable materials (CVCM) is 0.03%, which can satisfy the vacuum outgassing performance requirements of materials in space environment. At last, a typical PEEK starboard antenna pointing mechanism was prepared for aerospace applications in this study.