[Objective] As the proportion of renewable energy in the power system continues to rise, grid-forming converters have garnered significant attention and research interest due to their superior voltage support capabilities. However, in remote low-voltage distribution networks, the ratio of line resistance-inductance is relatively high. This can lead to power coupling issues in grid-forming converters, adversely impacting their fundamental voltage support and power transmission capabilities. This paper addresses the power coupling issues in grid-forming converters, considering changes in the resistance-inductance ratio in distribution networks. A control strategy employing feedforward decoupling is proposed. [Methods] The robustness of the system was improved by adding low-pass filter (LPF) into the decoupling channel. The impact of different LPF bandwidths on system stability was analyzed using the small signal method. [Results] Upon implementing feedforward decoupling, the coupling between the active and reactive power control loops was significantly reduced, effectively resolving the power coupling issues caused by the high resistance-inductance ratio of the distribution network. [Conclusion] The proposed method can achieve effective decoupling and provides a highly robust control strategy for power transmission in grid-forming converters.