JELLY OS is an interactive operating system that is based on AI technology. It provides a human-computer interaction solution for the family and commercial service robots. For the interaction system, we simplified the user input to robot output process and designed an active output system for a more humanized experience. For the visual presentation, we utilized the modern art concept of flat design with point, line and surface as the basis. With these elements, we created a human-like image for the JELLY OS robot that is full of emotions and a simple cum practical interface to convey messages in an accurate and artistic manner.