pH is one of the important parameters of the ocean carbon cycle system. The existing pH standard material is prepared with purified water buffer solution, while the pH of seawater reference material in artificial seawater can eliminate the liquid junction error, which is more suitable to the analysis of the various components of the carbonate system. So it is necessary to study production method of the seawater pH of standard material, and make it commercially available in the market. This paper describes the research principle of seawater pH of standard material production device, and the process of the production of the device from degassing, quantitative allocation and packing. The production device is verified by test from the middle process control and standard substance completed product verification. The test results show that the seawater pH of standard material production device has a basic production ability and some suggestions are put forward for the future work.