The invention provides an optical module comprising a circuit board, a light emitting sub-module and a flexible circuit board; the light emitting sub-module comprises a shell and a ceramic switching block plated with a metal layer, one side of the ceramic switching block is inserted into the shell, and the other side of the ceramic switching block is exposed outside the shell; signal and grounding bonding pads are arranged on the metal layer of the ceramic switching block, and the signal bonding pads on the inner side and the outer side of the ceramic switching block are connected; an isolation groove is formed between the signal bonding pad and the grounding bonding pad located on the outer side of the shell and on the ceramic switching block, and the isolation groove is sunken in the signal bonding pad and the grounding bonding pad; and one end of the flexible circuit board is connected with the ceramic switching block, and the other end of the flexible circuit board is connected with the circuit board. The isolation groove is formed between the signal bonding pad and the grounding bonding pad, exposed on the outer side of the shell, on the ceramic switching block, the isolation groove is sunken in the signal bonding pad, the dielectric constant of the ceramic switching block is reduced through the isolation groove, impedance discontinuous points at the connecting position of the flexible circuit board and the ceramic switching block are reduced, and thus the signal transmission quality is improved, and the signal integrity is ensured.