The invention discloses an optical module, comprising a substrate and a chip welded with the substrate by adopting a flip chip bonding method, wherein the gap between the substrate and the chip is filled and sealed by transparent silica gel, and the substrate and the exterior of the chip are encapsulated by pouring sealant. The invention also discloses a manufacturing method of the optical module. In the invention, common pouring sealant is adopted, and a secondary pouring process is utilized, thus the problem of encapsulation failure caused by mismatching of CTE (coefficient of thermal expansion) of the chip and the substrate in the optical module is successfully solved.