As the dream of “clasping the moon in the Ninth Heaven and seizing turtles deep in the Five Sea” gradually turns into the real footprint of China’s science and technology development, the new tasks and visions of deep sea and deep space exploration become increasingly challenging, calling for the support of innovative principles and technologies. This paper reviews the general development of operating equipment and soft robots for extreme environments and outlines the system principle and design method of the deep-diving experiments the robot with a soft-rigid fused structure conducted over 10 km deep down the Mariana Trench. Finally, the idea of exploration of Europa’s deep sea based on this principle is proposed to provide a reference for the development of deep sea and deep space exploration technologies.