This study aims to propose a structure of axicon-lens-axicon phase lens group. The structure is simulated and analyzed theoretically. The experimental verification is conducted using the rapid 3D printing technology to prepare an axonal pyramid, and a terahertz Bessel beam with 1000 mm diffraction-free length is generated. The results indicate that the diffraction-free region of such a beam is no longer proximal to the axial pyramid, but has a 100 mm distance from the final axicon. The findings in this study are helpful for the application of a terahertz Bessel beam in the field of large depth of field imaging.