Concerned about the increasingly harsh marine ecological environment, the sharp decrease in the number of coral reefs in the "tropical rain forest in the ocean", the high time cost and economic cost of artificial restoration of coral reefs, and the low safety factor, we independently developed and produced the coral restoration underwater operation robot-Shanhai II. To repair coral reefs, the first technical indicator that needs to be met is "diving depth". With the continuous increase of the diving depth, the pressure on the underwater robot cabin will increase. After considering the underwater pressure, corrosion resistance, cost and other factors, we selected "high-strength aluminum alloy and PMMA material" to construct the shell cabin, so that the maximum diving depth of "100 meters 」. In addition, in order to make the robot more flexible and efficient in underwater movement, we have installed four "high-power underwater propellers" in the vertical and horizontal directions of the underwater robot 」. In order to reduce the operating threshold of underwater robots, we independently developed the relevant "upper computer program" and "mobile phone app 」. Users only need to use the keyboard or click on the touch screen to control the movement of the underwater robot and the grasp of the mechanical arm, the operation is more humane, easy for beginners to get started. At the same time, we have also configured a "master-slave control mode" for the robotic arm. The shore-based operator can control the movement and grab of the underwater slave robotic arm by manipulating the small master robotic arm developed by us. In order to provide more angles for the robot operator and enhance the accuracy of the control, our robot is equipped with "three ultra-low-light cameras" and the captured content is displayed on the host computer in real time. With the unremitting efforts of our R & D team, the underwater robot we developed and produced has been more mature in technology, and has been tested underwater and coral reef restoration for many times. The test process robot showed the characteristics of safety, reliability and high repair efficiency, and was highly recognized by our school and related parties. The underwater robot uses "Raspberry Pi" and "STM32F407" to form the core master control platform. Use "DPE high-density polyethylene material" and "2020 aluminum alloy profile" to build the machine shell structure. The structure in the high pressure environment also has good compressive capacity, at the same time in the external general impact can also use their own good mechanical structure of this part of the impact energy self-buffering and absorption, so that the robot's own structure will not be too much damage, reduce the failure rate. Its structure is mainly composed of: electronic cabin, battery cabin, external grab structure, sensor structure and land control system.