Aimed at the problem that the conflict resolution effect under high load conditions is still not ideal, and the network performance cannot meet the requirements of cooperative attacks, this paper draws on the idea of using the power difference of NOMA technology to multiplex signals simultaneously, and introduces the power domain on the basis of the SPMA protocol time and frequency domain. For this, the paper proposes a strategy for improving the performance of the SPMA protocol in the joint power domain, expanding the channel resources of the data link network and achieving the goal of reducing further the probability of information collision. The results show that the improved strategy makes not only the data link network carry more business traffic, but also effectively improves network throughput and reduces network delay.