I repair my Equinox 2007 under seat after that the passenger airbag is shown OFF ?? I havnt seen any problem before under seat repairing .

HIYA!
All Equinoxes has yellow coloured wire harness to identify this as a air-bag system.
This yellow coloured wire 'system network' has connections in some areas...one is located at the front passenger's floor area close to the door (right-side corner area, just remove screw or clip and plastic trim part to gain access to see yellow wire there-it has socket plug connected with red clip-string to secure it) and another yellow wire is found between the front seats-you need to remove armrest, center console area and possible remove the front passenger seat to see yellow wire connect to black device underneath carpet in the middle.
Check to ensure the yellow wire sockets are plugged in properly, and not accidently cut or pulled off during your underseat repair.
In case your Equinox has roof side air-bag option, the yellow wire/sensor are located below the front seatbelt device inside the lower pillar frame area. (it's between the doors)
Hope this help you solve your repair task.