Harnessing the superior computational potential of quantum computing, an Adaptive Quantum Circuit for Dempster’s Rule of Combination (AQC-DRC) is proposed to facilitate quantum-level belief and plausibility decision-making based on quantum evidence theory (QET). The AQC-DRC achieves a deterministic realization of DRC, guaranteeing precise fusion outcomes without information loss, while exponentially reducing the computational complexity of evidence combination and markedly improving fusion efficiency. It is founded that the quantum basic probability amplitude (QBPA) in QET can be naturally used to express the quantum amplitude encoding. In addition, the quantum basic probability (QBP) in QET, which forms quantum basic probability distribution (QBPD), can be naturally used to express the quantum measurement outcomes for quantum belief level decision-making. Furthermore, the quantum plausibility (QPl) function in QET also can be naturally used to express the quantum measurement outcomes for quantum plausibility level decision-making. These findings open up new perspectives and enhance the physical interpretation of quantum measurement outcomes.