An optical module manufacturing method includes: forming a first waveguide layer and a second waveguide layer on a first substrate and a second substrate respectively, or forming a first waveguide layer and a second waveguide layer on a first surface of a first substrate and a second surface of the first substrate respectively; disposing the first substrate on the second substrate; disposing a filter at an end of the first waveguide layer and the second waveguide layer, so that the filter is aligned with the second waveguide layer; and disposing a prism on the filter, so that a first reflective surface of the prism is aligned with the first waveguide layer, and a second reflective surface is aligned with the second waveguide layer. Embodiments of the present application further disclose an optical module.