The invention discloses a photovoltaic junction box. The photovoltaic junction box comprises a diode module and a circuit board which are arranged in a box body, and a radiator inlaid in the outer surface of the box body. The diode module is attached to the back surface of the radiator and is electrically connected with a copper conductor; the radiator is made of an aluminum material; the radiator is internally provided with a heat absorption layer, and the heat absorption layer is close to the diode module. The aluminum radiator can greatly improve the heat dissipation capability of the junction box, at the same time, the metal temperature resistance is higher than that of conventional plastics, the box body is not easily deformed, and the safety and the reliability are high. According to the invention, the heat absorption layer is arranged in a radiator substrate, and since the heat absorption layer is close to the diode module, the portion, which is close to the outside, of the aluminum radiator can transfer heat absorbed by the heat absorption layer outwards while the heat absorption layer rapidly absorbs the heat for cooling the junction box, such that a plastic box body portion is prevented from deformation and the diode module is prevented from high-temperature damage because of the high-temperature states of the plastic box body portion and the diode module which are directly contacted with the radiator.