Abstract: A medical micro-robot moving in human intestine is proposed. The locomotion speed of the micro-robot and hydrodynamic mucus film thickness formed when the medical micro-robot moving in intestine with various diameters，various viscosity mucus and various modulus of elasticity are calculated according to the elastohydrodynamic lubrication theory. The results indicate that the medical micro-robot can be suspended to move quickly into intestine. The above results are proved by the experiments.

Key words: Endoscope, Low invasive locomotion, Medical micro-robot, Minimal invasive surgery