The invention discloses a method for fixing an oil testing pipeline. The method comprises the following steps: a, a hole slightly larger than the outer diameter of a limiting wheel of a fixing deviceis drilled at a place where the pipeline needs to be fixed, the device is placed into the hole, a control wheel of the fixing device is rotated clockwise to drive the limiting wheel to move downwards,then an expansion plate of the fixing device is driven to move downwards, under the action of a positioning cone of the fixing device the expansion plate expands outwards to squeeze the inner wall ofthe hole to realize fixation; b, after installation is completed, the pipeline is put into a pressing plate assembly of the fixing device, and bolts are connected to fix the pipeline; and c, after the work is finished, the control wheel is rotated counterclockwise to drive the limiting wheel to move upwards and then drive the expansion plate to move upwards and retract to relieve fixing, and thefixing device is take out. The method effectively solves the problem of oil and natural gas pipelines fixing, and has simple structure, low cost and high reliability.