The work aims to prepare stealth ink suitable for SLA 3D printer, and study the ink performance and the mechanical properties and stealth performance (microwave absorbing performance) of 3D printed samples. Photosensitive resins were used as ink binder and different contents of MWNTs/PPy/Fe3O4 composite materials were added to obtain stealth ink suitable for SLA 3D printer. The rheological properties and dispersion of the ink were tested. Test samples were prepared by 3D printing and their mechanical, electromagnetic, and stealth properties were analyzed. The content of different electromagnetic absorbers had a significant impact on the viscosity and dispersion of stealth ink, but had a relatively small impact on surface tension. The 3D printed sample with an absorbent content of 0.4 wt.% had good mechanical and stealth properties, with a maximum reflection loss of –23.36 dB. In conclusion, the stealth ink prepared in this study meets the requirements of SLA 3D printer, and the printed material has good stealth performance.