A creeping micro-pipe robot is designed, which comprises three DC motors and screw-driven units. The three motors are coordinated to realize the creeping motion. Firstly, the load is analyzed for the case that the robot creeps in a vertical pipe. Meanwhile, the mechanical adjustment characteristic for the claws to adapt to the varying pipe size is also discussed. Then with the help of ADAMS software, kinematical and dynamical simulations are presented, which shows the relationship between the driving force, the moving velocity and structural parameters of the robot. Simulations also demonstrate that the robot is applicable to pipes with diameter ranging from 15 to 20mm. The driving force reaches up to 28N and the moving velocity 6mm/s.