A quasi-Bessel beam can propagate over a long distance with its beam width unchanged, which provides a high beam aspect ratio, and is suitable for laser micromachining of structures. The propagation properties of quasi-Bessel beam generated by the ideal axicon and blunt-tip axicon are investigated. Strong peak oscillations occur due to interference between the quasi-Bessel beam and the refracted beam by the blunt-tip. Using the axicon for laser micromachining is theoretically calculated. Simple analytical formulas can be used to predict the required parameters, including laser pulse energy, generated fluence distribution, ablation width, beam aspect ratio and so on.