In friction hoist mine, the first ropes are replaced regularly. The existing replacing-rope methods are time-consuming, difficult to replace rope, easy to cause damage to the first rope, greatly reduce the service life of the first rope, severely restrict the production and affect mine safety. The first rope were replaced using the self-developed wellhead interactive new and old rope-exchanging system and equipments, and the qualitative safety to the ropes from sliding, the damages of steering wheel and the clamping body and resonance， were analyzed using the preliminary hazard analysis(PHA).The results showed that this method had the advantages，all operations at the wellhead, no fixing the cage, no affecting the tension difference by replacing-rope, high safety, less operators, less lifting time, high efficiency, so it could guarantee the safety of mine production, was a new kind of effective and safe method for replacing first rope.