The biting behavior of the kava on the casing directly determines the anchoring effect and affects the sealing stability of the packer cartridge. In order to improve the safety of the tubular column in offshore "three high" gas wells and ensure the good working performance of the kava, the HPC070401 packer bi-directional cartridge kava is used as an example. Taking HPC070401 packer bi-directional barrel type kava as an example, the mechanical behavior of kava biting process was studied by combining the slip line theory method, numerical simulation and experimental method, the contact stress distribution law between kava and casing, the depth of kava teeth biting into casing and fatigue life were analyzed, and the sufficient and necessary criterion of reliable work of packer kava system was established. The results of the study show that: ① the sitting card pressure increases, the depth of kava teeth biting into casing also increases, in the sitting card pressure of 35, 42, 48, 55MPa, the depth of kava biting into casing is 0.25993, 0.29425, 0.32353, 0.36561mm. ② the increase of the sitting card pressure, the localized plastic deformation of the kava tooth tip increases, but it has a certain effect on the fatigue cycle life of the kava. ②Increase in seating pressure increases the local plastic deformation of the kawa tip, but it has some effect on the fatigue cycle life of the kawa. Under the symmetric cycle fluctuation of 20% under the seating pressure of 35, 42, 48 and 55MPa, the symmetric cycle fatigue life of the kawa is 951110, 789540, 717160 and 629260 times. Through the high temperature and high pressure packer kava anchoring experiment, the measured depth of kava biting into casing is between 0.350 and 1 mm; ④ Combined with the evaluation criterion and the fatigue experiment of high temperature and high pressure packer, the stress relaxation coefficient of casing due to the fatigue cumulative damage is 0.18. The finite element simulation and the experimental results match well, and the results of the study can provide reference value for the design of high temperature and high pressure high yield gas packer kava structure.