Based on the construction process of trenchless HDD technology,this paper elaborates the working principle of the bit guide in horizontal directional drilling technology and comprehensively analyzes the influencing factors of the guiding strength,including the strength of rock and soil,the structure shape of the guide bit's inclined foot,the stiffness of the drill pipe,the washing fluid,the size and speed of the feed force.Through the calculation model,it is concluded that the strength of rock and soil,the structural shape of the inclined palm of the guide bit and the stiffness of the drill pi...