The embodiment of the invention provides a terahertz wave generator. The generator comprises a substrate, an N-type DBR reflecting mirror, at least two laser emission assemblies, a passivation layer,an N-type electrode, a P-type electrode, a grating layer and a non-linear crystal, wherein the laser emission assemblies are used for emitting laser, the N-type DBR reflecting mirror is deposited on an arbitrary end surface of the substrate, each laser emission assembly is deposited on each protruding structure, the passivation layer is covered and deposited on the laser emission assemblies and asurface of the N-type DBR reflecting mirror, an opening is formed in a first part of the passivation layer, the non-linear crystal is opposite to the opening and is fixedly arranged at a position at apreset distance with the opening, the N-type electrode penetrates through the passivation layer and is electrically connected with the N-type DBR reflecting mirror, the P-type electrode encircles theopening, penetrates through the passivation layer and is electrically connected with the laser emission assemblies, and a connection mode between the laser emission assemblies is in series connectionor parallel connection. The generator provided by the embodiment of the invention has high integration.