Provided herein is a multi-channel optical module including a plurality of laser diodes emitting light with different wavelengths, a thermoelectric cooling device including the plurality of laser diodes, a TO-can including the thermoelectric cooling device, and a holder combined with the TO-can and including a plurality of optical lenses focusing the light with different wavelengths and a multiplexer gathering focused light into a single optical fiber, wherein the holder has a shape in which the TO-can is cut along an axis of a path of the light with different wavelengths for active alignment of the plurality of optical lenses.