Abstract: A novel three degrees of freedom (DOF) parallel rolling robot is proposed. The main consideration for proposing the robot aims at acquiring large deformation capability, powerful strength output, rapid response and flexible locomotion. The robot adopts the parallel mechanism as its architecture to guarantee the stiffness of the robot. The large deformation capability is obtained by taking advantage of the planar expandable mechanism as the extension ratio enlarging mechanism. The usage of the hydraulic actuation as the telescopic input increases the locomotion flexibility and the strength output of the robot. The robot rolls by properly planning and controlling the relations between the center of mass (CM) of the robot and the supporting region. The mechanical construction and configuration of the robot is described, the rolling gaits are planned, and the optimal locomotion rule is given. Based on the rule, the kinematic model of the robot is built. The correctness of the kinematic model is verified by the given numerical example. The locomotion feasibility of the two locomotion periods is analysed. A set of experimental system including the hydraulic system and robotic system is built. Four rolling experiments are carried out accordingly. The experimental results demonstrate that the experimental system is reliable and possesses the rapid response capability, and verify that the validity and feasibility of the theoretical analysis and the rolling locomotion.