Choroidal metastasis is one of the most common malignant tumors inside the eyes. It causes pain, hypopsia and some other related symptoms. It reduces the quality of the patients' life. It's significant for the patients to be detected and treated early, therefore they will have better vision and longer life. The treatments of choroidal metastasis are developing quickly. Both the vitreous cavity injection of targeted drug and gene therapy are hot topics of research. This paper summarizes the etiology, development, diagnosis and treatment of choroidal metastasis nowadays.