The invention discloses a solar battery bus bar welding device. The solar battery bus bar welding device comprises a welding platform, a laser unit, a sensor and a laser regulating mechanism, whereinthe laser unit is arranged above the welding platform; the laser regulating mechanism is connected with the laser unit; and the sensor is arranged on the surface of the welding platform. The solar battery bus bar welding device disclosed by the invention adopts a laser welding way to replace a conventional manual soldering iron welding way and a conventional resistance heating welding way, is matched with the laser regulating mechanism to regulate power of the laser unit according to the needs, and can control precision and uniformity of a bus bar welding temperature better. Compared with theprior art, the solar battery bus bar welding device can improve the bus bar welding quality, prevents the bus bar and a drainage bar from position deviation, reduces bad phenomena of insufficient welding, welding skips and the like, and improves integral performances of a photovoltaic module.