Abstract: A quasi-macroscopic cold field emission electron gun and a manufacturing method thereof are provided, which includes a filament device and an electron gun base, wherein the filament device includes a cold cathode filament and a conductive capillary tube, the cold cathode filament passes through one end of the conductive capillary tube and is crimped through a pressing groove device, the other end of the conductive capillary tube is connected to the electron gun base, and the end of the cold cathode filament is the electron emission end. Through the coaxial nesting and pressing deformation of quasi-macroscopic carbon fiber and metal tube and using of the non welding electrical connection method, this technology avoids the problem that it is not easy to form a reliable electrical connection during the welding process due to the poor wettability between carbon fiber and metal.