An optical inspection system includes a first optical module and a second optical module. The first optical module includes a first light source having a first optical axis and a first image capturing unit having a first image capturing axis. The first optical axis and the first image capturing axis are symmetric relative a normal line of an inspection plane. A first angle is formed between the first optical axis and the first image capturing axis. The second optical module includes a second light source having a second optical axis and a second image capturing unit having a second image capturing axis. The second optical axis and the second image capturing axis are symmetric relative to the normal line. A second angle is formed between the second optical axis and the second image capturing axis and is different from the first angle.