We focusing on investigating the protection of meter-class REBCO no-insulation (NI) coils applied in next generation high-field magnetic resonance imaging scanners. In order to address the issue of controllable contact resistance, we proposed a method is based on an external variable resistance, which is paralleled with an NI coil to realize the controllable contact resistance. It can maintain the temperature increase of the coil in the safety range during a charging and discharging by the efficient leading-out the electromagnetic energy. To certify the feasibility of this method, in this study, a numerical analysis was conducted of a partial element equivalent circuit along with a thermal analysis of a simple equivalent circuit model to investigate the effective range of variable resistor to realize the protection method for the meter-class NI coil. Based on the results, we discussed the feasibility of the inhibitory effect of variable resistor on the temperature increase of meter-class NI coil and the energy dissipation rate during a sudden discharging.