The embodiments of the present application disclose an emitter, an emitting module, and a LiDAR. The emitter includes a laser, a driving circuit, a substrate, and a heat conduction member. The laser and the driving circuit are both mounted on the substrate, and the heat conduction member is connected to the substrate, with at least the portion of the substrate used for mounting the laser being in contact with the heat conduction member. Mounting the laser on the substrate and having at least the portion of the substrate used for mounting the laser in contact with the heat conduction member facilitates timely and efficient heat dissipation from the laser through the heat conduction member, improving the heat dissipation rate around the laser and avoiding local hot spots at the laser, thereby ensuring the normal operation of the laser.