Choke manifold is necessary device to control the well kick successfully and execute the pressure control technology on oil/gas well in the course of drilling, as it is, the device is adopted to execute new drilling-well’s technique of balance pressure, which can avoid pollution of oil-layer, improve the speed of drilling and control blowout effectively. One end of the device connects with the side flange of BOP spool. When BOP closes, it can control the finite pressure from casing by adjusting the choke valve’s opening, so balanced drilling can work under minimum pressure-difference.