An optical module includes a lens assembly and an optical fiber holder. The lens assembly includes a lens base, a first positioning column and a second positioning column. The optical fiber holder includes a first positioning hole and a second positioning hole. The first positioning hole is disposed on a second assembly surface and corresponds to a position of the first positioning column; the first positioning hole has an opening on the second assembly surface and an opening on a first side surface connected with the second assembly surface, and the two openings are connected. The second positioning hole is disposed on the second assembly surface and corresponds to a position of the second positioning column; the second positioning hole has an opening on the second assembly surface and has an opening on a second side surface connected with the second assembly surface, and the two openings are connected.