Abstract: In this paper, 52 earthquakes recorded by the Jiangsu Seismic Network from 2013 to 2018 in the South Yellow Sea area are relocated using three types of locating methods: Simplex algorithm, HypoSAT, LocSAT according to the spatial distribution of earthquakes and regional characteristics of seismic structures under the iasp91 and south China velocity models. The results show that the stability of the source depth decreases with the increase of the gap angle. Simplex algorithm is less dependent on the velocity model, but more closely related to the gap angle. Under the two models, LocSAT results have no obvious dominant depth and are significantly affected by seismic phase factors. The HypoSAT method has a relatively wide application range and stable calculation results. Under the iasp91 model, it is more suitable for the determination of the source depth of the south yellow sea earthquake, which can meet the needs of the current daily work.