Abstract <p>The results of simulating different options of implementing electron cyclotron resonance (ECR) plasma heating at the GOL-NB multiple-mirror trap are presented. For a model radial profile of plasma density, the propagation and absorption of waves of the ECR frequency range were studied for both the existing magnetic configuration and feasible one with an increased magnetic field in the central trap. The simulations showed that for the frequencies of 37 and 54.5 GHz, it is possible to efficiently heat plasma by extraordinary wave at the fundamental harmonic. At the same time, there is a problem of “spurious resonance”, occurring on the “outer” part of the cyclotron resonance surface from the low-field side. For frequencies of 75 and 95 GHz, plasma heating by the extraordinary wave at the second harmonic can be relatively efficient for electron temperatures higher than 100 eV, which exceeds the plasma temperatures currently achieved in the experiment.</p>