The stress of the breasting dolphin jacket of a 300 000 t oil tank terminal is analyzed under the effects of environments and ship loads in an open water area with water depth of 100 m. Taken inspiration from offshore oil and gas jacket platform structures and combined with the characteristics that the breasting dolphin jacket structure mainly bears horizontal ship loads, the structure of the breasting dolphin jacket with eight-leg columns and skirt pile foundations is designed. The finite element software Ansys is used to establish the structural analysis model and the static analyses of the breasting dolphin jacket structure are conducted under four different working conditions based on environmental conditions and load combinations. The results show that the displacement and stress of the jacket structure reach the maximum during ship berthing, mainly appearing at the position of the main leg column near the mud surface and the structural stress satisfies the allowable stress requirements. The research indicates that using a jacket structure for a large oil tanker terminal with water depth of 100 m is feasible, and it provides valuable insights for the selection and design of deepwater oil tanker terminal structures.