The invention provides a terahertz light source chip and a manufacturing method thereof, a terahertz light source device and a manufacturing method thereof, and a terahertz light source module and a manufacturing method thereof. The light source chip comprises a two-dimensional electron gas mesa, an electrode, a terahertz resonant cavity and an optical grating, wherein the electrode is formed on the two-dimensional electron gas mesa and used for exciting plasma waves; the terahertz resonant cavity is formed below the two-dimensional electron gas mesa, and a holophote is arranged on the bottom surface of the resonant cavity; the optical grating is formed on the two-dimensional electron gas mesa and used for coupling a plasma wave mode to a terahertz resonant cavity mode so that terahertz wave emission can be generated. Plasma polaritons are formed by strongly coupling the terahertz resonant cavity mode to the plasma wave mode in two-dimensional electron gas under the optical grating, terahertz wave emission can be generated through electric excitation of the plasma polaritons, the problem that terahertz emission is low in frequency or working temperature because of high frequency oscillation relaying on a single electron or quantum jump relaying on a single electron is solved, and the emission frequency range and the working temperature range are widened.