With the rapid growth of satellite communication demands, the scarcity of spectrum resources has become increasingly prominent. To ensure full utilization of system bandwidth and reduce the performance gap between adjacent 2²ⁿ-order Quadrature Amplitude Modulation(QAM) superposition schemes, this paper investigates the application of a 2²ⁿ⁺¹-order-based superposed 32QAM scheme in Non-Orthogonal Multiple Access(NOMA) satellite networks. First, a 32QAM constellation formed by superposing a novel 8QAM and Quadrature Phase Shift Keying(QPSK) is designed, and joint encoding is employed between two users to achieve rotation of the 8QAM signal. Then, to obtain the optimal superposed constellation with the objective of maximizing Constellation-Constrained(CC) capacity, the optimal power allocation algorithm is simplified under high Signal-to-Noise Ratio(SNR) conditions. Simulation results demonstrate that when Mutual Information(MI) exceeds 4.98, the proposed scheme achieves a 0.29 wider range of power coefficient ratios compared to the square 8QAM+QPSK scheme, and its Bit Error Rate(BER) performance outperforms the other three schemes(square 8QAM+QPSK, conventional 8QAM+QPSK, and superposed 32PSK).