Abstract: In dam construction, the competition of conflicts in cross operation space is a major root of construction accidents. To study such competition, first we analyze the characteristics of cross operation of dam construction, describe the paths from spatial conflicts to accidents, decompose the processes of concrete transport, spreading and vibration, and identify the cross operation cases featured with spatial conflicts. Then, the influence space of hazardous installation process and the workspace of a hazardous body process are defined by using the paths of damaging energy flows and the characteristics of the hazardous body process respectively in combination with geometrical properties of hazardous bodies like a human, machine or facility. Finally, we determine the competition of cross operation spatial conflict strength by calculating the probability of the overlapping area covered by different damaging energies and the probability of the hazardous bodies coming into this area. The results show that the strongest competition occurs during the vertical transport of the cable crane and it could be lowered by reducing the vertical distance between the cable crane and construction storehouse surface.