A puncture repair liquid injection method injects puncture repair liquid into a tire by using a puncture repair liquid injection device provided with a container having a liquid containing portion containing a puncture repair liquid, along with an outlet for discharging the puncture repair liquid, and an inlet for introducing compressed air; an injection hose connected between a tire valve of a wheel mounted on a tire and the outlet of the container; and a compressor having a pressure adjuster for selecting an air pressure. The method further comprises connecting the injection hose between the tire valve and the outlet of the container, connecting the compressor to the inlet of the container, selecting a reduced air pressure as a pressurizing force by the compressor by an operation of the pressure adjuster, and injecting the puncture repair liquid into the tire by pressurizing the container interior.