In this manuscript, a new deformable robot with spherical rolling and quadruped walking ability is proposed, and the robot mechanism can be changed to different modes according to the terrain. The deformable mechanism keeps the robot movement with high motion efficiency and energy saving in flat terrain, and enhances the motion adaptability to unstructured terrain. Moreover, integrated mechanism improves the motion flexibility for traditional rolling and quadruped walking, wheel-leg motion and rapid walking are possible. Series of simple motion in different motion modes and motion conversion between different modes were tested in real environment, and comprehensive performance in complex task was evaluated by simulation. Test results show that the proposed flexible deformable robot with enhanced movement ability in unstructured terrain can truly improve the execution performance of real tasks.