Collision detection is pretty important in Virtual Reality, and its speed greatly influences the reality and illusion of immersion in virtual environment. We propose a collision detection algorithm of hybrid bounding box based on the merits of AABB and OBB: AABB-OBB. It is applicable to solid objects. We construct simpler bounding volume tree and apply improved data structure to decrease storage space. During the period of traverse AABB-OBBTree, we have applied single traverse method to improve the efficiency of collision detection,and its effect is more obvious especially when the depth of trees is different greatly.