Despite the rich spatiotemporal patterns contained in trajectory data from multiple Location-Based Social Network (LBSN) platforms, heterogeneous formats, semantic inconsistencies, and unequal user scales across platforms create substantial barriers to reliable identity mapping. Furthermore, GPS drift and sparse sampling result in degraded data quality and distribution imbalance, which render existing trajectory representation methods inadequate for capturing high-order dependencies and dynamic spatiotemporal evolution patterns in heterogeneous multi-relational graphs. To this end, we propose HANCUA (Hierarchical Attention Network with Correction for User Association), a novel framework that employs a dual-stage correction mechanism to enhance cross-domain trajectory analysis. The approach constructs hierarchical multi-relational graphs comprising location, trajectory, and correction layers to capture fine-grained mobility patterns, behavioral associations, and inter-platform distribution differences. We design relation-aware multi-head graph attention networks to model complex interactions among heterogeneous node types, which enables comprehensive spatial relationship modeling. A spatiotemporal semantic collaborative learning module integrates temporal information with mobility patterns through interaction-aware attention mechanisms, while an ensemble correction decision module incorporates ensemble learning principles to systematically correct user association biases and address distribution imbalance problems. Extensive experiments on two real-world LBSN cross-domain datasets reveals that HANCUA significantly outperforms state-of-the-art methods in user identity linking accuracy.