Abstract: Based on comparison of firing procedures of tubing conveyed perforation currently in use in China,irrational sealing design of annulus pressurizing and pressure trans-mitting system is believed to be the cause of that the perforated string of annulus pressurized tubing conveyed perforation cannot support high pressure and is not suit-able for use in deep wells or in wells with slow pressure build-up.After design optimization,the sealing pressure that the annulus pressurizing and pressure transmitting system can support is over70MPa and surface pressure testing can be performed.