The objective of this study was to develop a new X-ray collimator. Electron beam lithography （EBL） technology was coupled with electroplating and wet chemical etching technology to fabricate gold micron gratings involving a large area and high aspect ratio on a suspended silicon nitride membrane. The exposure dose in the field splicing area was adjusted to solve the large area EBL problem. The grating line collapse in high-aspect ratio and high-density photoresist templates was overcome by using a reinforced structure. The thick photoresist spin-coated fracture on the 300-nm Si₃N₄ membrane was prevented by keeping an extremely thin layer of silicon （25 nm thick） under the thin Si₃N₄ membrane； therefore， improving the development process. The results demonstrated that the gold gratings with a 2-μm period， 5.5 aspect ratio， and 400-μm by 1000-μm area can modulate the 8-keV energy X-rays. The fabricated gold gratings can be used as detector collimators in line-parallel X-ray tomography systems or as source collimators in area-parallel X-ray tomography systems to improve the imaging speed.