Abstract: Aiming at the problem that the seal of the self-sealing packer is liable to be broken due to wear and corrosion of the seal cylinder and consequently the oil-gas cannot be exploited in layers, a set of isolation and seal performance test pipe string technology is developed. Through the pressure gauge and flow meter data built into the test pipe string, the damage of the sealed cylinder can be effectively detected. According to the existing standard "Oil and Gas Compression Packer Rubber Cartridge", different specifications of new types of sealing tool cylinder are designed to meet the requirements of different sealing types. First, the size parameter and the hardness of the rubber tube are prioritized. Then, the rubber tube of the testing tool is subjected to a sealing test, a pressure resistance test and a sealing performance test, therefore the compression distance and the sealing force of the sealing tool corresponding to the sealing cylinders of different specifications are determined. The inspection process is used to carry out on-site inspection of the stratified failure wells, and the sealing cylinder is used to effectively seal the damaged one. The result shows that the developed detection process technology can effectively ensure the stratified mining in the oil-water well with the defective seal cartridge.