The application of titanium-antimony composite catalysts in large-capacity polyester units was primarily investigated. In the early small-scale tests, by comparing the performance of ethylene glycol antimony catalysts and titanium-antimony composite catalysts in different ratios, it was found that the latter exhibited higher catalytic activity and better thermal stability during polyester synthesis. The use of titanium-antimony composite catalysts significantly shortened the esterification and polymerization reaction times. Additionally, the titanium-antimony composite catalysts demonstrated good adaptability and operability in large-capacity units. Compared to standalone ethylene glycol antimony catalysts or titanium-based catalysts, it reduced the content of heavy metal antimony in the fiber while ensuring the quality of the melt.