The balance of original natural environment will certainly be broken during construction of water conservancy engineering. Simultaneously, the balanced system in construction region will be interfered. The const ruction results in the unstablility of regional geology structure, so stable issue of geo-envi ronment is caused.The relevant relation between environmental effect and water conservancy engineering, the relation between water conservancy engineering and unfavorable factors are analyzed, and suggests that deep and detailed investigation and research works for geo-technical environment engineering should be carried out, so as to overcome unfavorable factors and enlarge the environmental effects during the process of design, construction as well as the management of construction.