As language model agents leveraging external tools rapidly evolve, significant progress has been made in question-answering(QA) methodologies utilizing supplementary documents and the Retrieval-Augmented Generation (RAG) approach. This advancement has improved the response quality of language models and alleviates the appearance of hallucination. However, these methods exhibit limited retrieval accuracy when faced with massive indistinguishable documents, presenting notable challenges in their practical application. In response to these emerging challenges, we present HiQA, an advanced framework for multi-document question-answering (MDQA) that integrates cascading metadata into content as well as a multi-route retrieval mechanism. We also release a benchmark called MasQA to evaluate and research in MDQA. Finally, HiQA demonstrates the state-of-the-art performance in multi-document environments.