Abstract: In order to ensure the accurate measurement of K ₁ value of cuttings gas desorption index, the measuring principle of K ₁ value was studied, and the key factors to be grasped in the development of cuttings gas desorption instrument were put forward. The factors include the mass of coal sample G, exposure time t ₀ from the beginning of gas discharge to the starting of gas desorption instrument, and pressure value p _i at each measuring point. Based on the core elements influencing the determination of K ₁ value, the instrument structure, electronic circuit design and theoretical algorithm were analyzed. The factors affecting the measuring accuracy of the instrument in the development process were determined, and the design recommendations of reducing the t ₀ error, speeding up the starting time, and paying attention to the structure and algorithm of the leak and plugging were put forward. It can be used for reference by the developer of gas desorption instrument.