With a hypothesis that energy is completely absorbed by plasma in a plasma slab model and a three-dimensional antenna model,we numerically stimulate coupling of two strip antennas with plasma in ion cyclotron resonance heating.Antenna radiation power and power density distribution absorbed by plasma at different antenna distances are calculated.Through analyzing we draw a conclusion: For two strip antennas feed in phase at certain experimental parameters,the shorter the antenna distance is,the better ion cyclotron resonance heating is.