Method for lifting tubular column under pressure

The invention belongs to the technical field of under-pressure operation, and discloses a method for lifting a tubular column under pressure, which comprises the following steps of: installing required equipment and devices; the pipe column is lifted to the oil pipe with the blanking plug, the coupling of the oil pipe with the blanking plug is stopped above the ball seal of the under-pressure operation equipment, and the oil pipe on the coupling exposed out of the ball seal is detached; the connector is connected with an oil pipe coupling, and the flange plate is connected with the ball seal; releasing the pressure above the lower working semi-closed flashboard through an emptying valve of the under-pressure operation equipment, and then opening the ball seal; the pressure in the well is guided into the lower cavity of the casing pipe through the balance valve, and when the oil pressure of the upper cavity is equal to the pressure in the well, the built-in slip is loosened, and the lower safety semi-closed fl