For developing the control technique of air in the manned spacecraft cabin, the CO2 simulate control‐testing equipment is developed to study the CO2 removal equipment in the carbon air. The developing process is introduced in this paper. On the basis of overall design, the authors emphasize the study of the cabin interface design and draw a conclusion that disposing the entrance of the gas at the same side of the cabin content the gas intimate mixing. In the design of the flow meter, using the plastic rotor can solve the problem of flow meter pressure loss which is too much by using the glass rotor.