When drilling long horizontal wells, the axial vibration generated by the drilling string at the bottom hole will effectively alleviate the phenomenon of “frictional drag of the drill bit”, which can reduce the friction and enhance the penetration rate. Based on the principle of vibration impact, the axial vibratory tool for friction reduction with a diameter of 127 mm was designed, and the mechanical structure and working principle of this tool were also introduced in detail. First, the planar planetary motion of the throttle valve was described, and a model for calculating the cross-flow area at different moving valve and fixed valve sizes was established. Then, considering the effect of local head loss, the mechanical analysis of the working pressure drop generated by the fluid at each site within the dynamic short connector was carried out, and the relationship curves of the working pressure drop with time and cross-flow area were obtained. After that, the Viscous-Realizable k-ε turbulence model was used to simulate the water hammer pressure of the dynamic short connector, and the variation of water hammer pressure with time, cross-flow area, and cross-sectional flow velocity under 3D/2D conditions was obtained. Based on the undamped vibration differential equation, the axial impact force and axial vibration displacement generated by the vibratory tool were solved. The calculated results are in good agreement with the experimental test results. The field test of this vibratory tool was conducted in well FNHW4084 of the Mahu oil field in Xinjiang, China. The tool was in the well for 10.68 days. The drilling fluid was circulated for 202 h. The pure drilling time was 125.83 h. The drilling footage of a single tool is 596 m with an average penetration rate of 4.74 m/h. Rate of penetration in the test section was increased by 254% compared with the upper section. Compared with the same kick-off section of the neighboring well FNHW4026, the one-trip drilling footage of the test section was increased by 150% and the penetration rate was increased by 126%. The field test results present that this vibratory tool can significantly increase the drilling footage and penetration rate of horizontal kick-off section.