Pipe cleaning and inspection robot is one of the new concepts of professional service robots. Sewer pipes are typically of non-man-entry classification (less than 0.8 m diameter). In this paper, a pipe-cleaning and inspection robot specifically designed for this function is proposed. This paper presents a new approach for design and development of cleaning robots in an unknown pipe workspace. To do so, we propose a new cutting method for cleaning work as well as an underwater inspection method. In this study, we discuss a communication which makes the cleaning robot navigate the sewer pipe. Finally, we also evaluate the performance of our proposed inspection and cleaning processes via experiments and real tests. Also, we verify the effectiveness of the proposed methods through computer simulations.