A soft crawling robot driven by a single twisted and coiled actuator is proposed and tested. This robot has a small and simple structure which only weighs 9 g. Also, fabrication of this robot is very easy, materials used to make this robot are silicone, paper clips, fish line, and hot melt glue, which are easy to be obtained and the cost is very low. The mechanism of the proposed robot is discussed in detail: the robot has two special feet with the function of friction change and it uses the bending deformation of its soft body to make friction changes so that it crawls. The principle of the crawling step control is introduced. The fabrication progress of the robot is demonstrated, a prototype is fabricated to verify the mechanism and to test the crawling posture and speed. It crawls at a speed of 1.2 mm/s with only one twisted and coiled actuator (TCA).