The invention provides a SAGD shaft liquid extrusion pretreatment method. The method comprises the following steps: a liquid extrusion pretreatment device is assembled as follows: an outlet of an injecting pipe is connected to a middle pipe to form a first tee joint; a first end of a short pipe connecting pipe is connected to the middle pipe to form a second tee joint; a third end of a long pipe connecting pipe is connected to the middle pipe to form a third tee joint; and then, a first switch valve, a second switch valve, a third switch valve, a fourth switch valve and a fifth switch valve are provided; the liquid extrusion pretreatment device connects an injecting pump with a SAGD shaft as follows: an inlet of the injecting pipe is connected to the injecting pump; a second end of the short pipe connecting pipe is connected to a short pipe of the SAGD shaft; a fourth end of the long pipe connecting pipe is connected to a long pipe of the SAGD shaft; and the injecting pump and the liquid extrusion pretreatment device are used for injecting and draining liquid in and out from the short pipe and/or the long pipe. The method can satisfy the requirements of the SAGD shaft liquid extrusion pretreatment method on the ground flow pipe manifold.