The invention discloses a method for measuring the power frequency grounding resistance of an iron pipe tower with double ground wires, 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 under the condition that one ground wire is opened, 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 two ground wires are disconnected from tower metal.