With the advancement of engineering construction such as urban subway tunnels and railway tunnels， the horizontal directional geological exploration method has become a new exploration method. Compared to traditional vertical hole construction， it can avoid complex construction environments， save a lot of drilling workload， and have obvious technical and economic advantages. The tunnel directional drilling system has traditional advantages for surface or tunnel exploration， but the horizontal exploration mainly based on coring has higher requirements. The tunnel directional drilling technology needs targeted improvement and upgrading in aspects such as coring process adaptability and drill function module. Focusing on the technical characteristics of horizontal directional exploration， this paper compares and analyzes the adaptability of typical tunnel directional drilling systems in aspects of drill pipe system， horizontal exploration rig， drill assembly and coring tool， directional drilling instrument and drilling informatization， and summarizes the technical integration that must be relied on to build the tunnel horizontal exploration engineering technical system. In response to the requirements for efficient coring operations and variable track drilling operations， the direction for the transformation of the horizontal exploration drilling rig’s high torque and strong feeding capacity， multi process adaptability， efficient drilling capacity， efficient tripping capacity， coring capacity， and power head structure has been clarified. Analyzed the shortcomings and limitations of using rope core drilling tools in directional holes with frequent trajectory changes， and explored the types of information parameters and transmission paths in the process of drilling informatization.