From 2010 to 2012, China and South Korea launched inter-governmental negotiations. South Korea also signed FTAs with US and EU. The effect of China-ASEAN FTA and South Korea-ASEAN FTA also worked gradually, which leads to the adjustment of import and export structure and industrial structure in China and South Korea and will affect the economic effect of China-South Korea FTA. Considering the concession of tariffs in the FTAs that have been signed and taken effect by China and South Korea and their different sensitive products, this paper uses GTAP model to re-simulate the economic effect of China-South Korea FTA. The changes of the effect of China-South Korea FTA are analyzed from three aspects: GDP, import and export, and different industries, which will provide more accurate data support for China’s FTA negotiations.