As technology and equipment improves, the horizontal directional driller was gradually accepted in the developed countries in the 1980s. With the rapid construction of urbanization, non-excavating technology is widely used in China. In this paper, a new kind of hybrid technology in the horizontal directional driller is presented. Taking HL518B as a prototype, a parallel hybrid system is designed .The control strategy of the hybrid horizontal directional driller is analyzed on the basis of the several operations in the working cycle. The control goal of whole system is to realize the torque demand of loading. Research is made on how to transform the single engine power into the hybrid power train, At same time the model of hybrid system is established and simulated. The simulation results show the hybrid system can effectively improve the horizontal directional driller fuel economy.