Abstract
According to the features of heavy horizontal directional drill hydraulic system, power head hydraulic system which is the main working mechanism of the 280t horizontal directional drilling is modeled and simulated base on Amesim. On that basis, we adjust working characteristics of this model and make the point of view that feedback control parameters which is the hydraulic system of heavy drill should be adjusted according to the soil conditions. So that it can enhance the utilization rate of the machine power and drilling efficiency in different operating modes.