The invention discloses a method for measuring the power frequency grounding resistance of a single ground wire iron pipe tower, which can greatly improve the test efficiency and the test accuracy, discover bad grounding in time and improve the lightning withstand level of equipment. The method comprises the following steps: (a) checking a ground electrode of the iron pipe tower, recording and timely processing abnormalities that a ground wire is damaged or a bolt is stolen and the like; (b) measuring the grounding resistance of the iron pipe tower using a clamp meter method without detaching the ground wire, checking whether ironware connecting bolts are loosed or in bad contact if the grounding resistance of the iron pipe tower is obviously increased relative to the grounding resistance of other surrounding tower and the conventional value of the iron pipe tower or exceeds the provision of the corresponding standard or regulation on the grounding resistance, re-measuring the grounding resistance after excluding, and executing step (c) if the grounding resistance is still increased or exceeds the standard; and (c) measuring the grounding resistance of the iron pipe tower using a three-pole method under the condition that the ground wire is disconnected from tower metal, checking whether the ground electrode is unqualified or the ground wire at the upper part of the tower is in bad contact and the like, judging the reason and making corresponding reformation.