An airtight sampler with the function of holding pressure and coring was designed. First, using the sediment sampling test platform, taking high sampling rate as the goal and the motion speed of manipulator as the constraint condition, the sediment sampling rate (ratio of the sample retrieved by the sampling tube to the insertion depth of the sampling tube) test under different sampling tube inner diameters was carried out, respectively. Then, the pressure drop calculation and analysis of other components such as pressure retaining cylinder and sealing cylinder during the recovery of the airtight sampler to the deck are carried out, and the pressure drop compensation during the recovery of the airtight sampler is calculated and analyzed based on the pressure compensator. At last, the internal pressure test, high-pressure cabin test, and adaptability test between sampler and manipulator are carried out by using the developed prototype of an airtight sampler for sediments in the deep sea. The test results verify the feasibility of the design of an airtight sampler for sediments in the deep sea, which will provide strong support for the deep seabed sampling operation of the manned submersible in the deep sea.