Swift response to public complaints is an important measure to realize intelligent social governance and improve people’s satisfaction. It is particularly crucial to analyze public complaints accurately to match work order processing departments intelligently, and to realize swift response and efficient handling of public complaints. However, the vague description of complaints, confusion of categories and imbalance of proportion in public complaint data lead to difficulties in analyzing categories of complaints, thus reducing the efficiency and accuracy of intelligent order dispatching. To solve the above problems, a hierarchical multi-label classification model (HMCHotline) for complaints with encoder-decoder structure was proposed. Firstly, the fine-grained keyword prior knowledge in complaint domain was introduced into the text encoder to suppress noise interference, and the spatio-temporal information in complaints was fused to improve the discriminant ability of semantic features. Secondly, the label hierarchy was used to generate label embeddings with hierarchy-awareness and semantic-awareness, and a label decoder based on the Transformer model was constructed to decode labels using the semantic features from the complaints and label features. At the same time,the dynamic label table strategy was introduced based on the hierarchical dependency to limit the decoding range of labels for solving the problem of label inconsistency. Finally, the Softmax grouping strategy was used to divide the label categories with the similar size into the same group for Softmax operation, which alleviated the problem of low classification accuracy caused by the long-tailed distribution of labels. Experimental results on Hotline, RCV1 (Reuters Corpus Volume I) -v2 and WOS (Web Of Science) datasets show that compared with Hierarchy-aware label semantics Matching network (HiMatch), the proposed model improves the Micro-F1 by 1.65, 2.06 and 0.43 percentage points respectively, proving the effectiveness of the proposed model.