The invention provides a method and an equipment for mixing friction welding by dual-shoulders. The method for mixing friction welding by the dual-shoulders comprises the following steps of adopting a main mixing head and an auxiliary mixing head on two surfaces of the metal to be inserted between two workpieces to be welded respectively; when inserting the main mixing head and the auxiliary mixing head into the position between the two workpieces to be welded at the symmetric positions to carry out the mixing friction welding operation, leading the distance of the main mixing head and the auxiliary mixing head to be more than 0; when inserting the main mixing head and the auxiliary mixing head into the position between the two workpieces to be welded at the asymmetric positions to carry out the mixing friction welding operation, leading the distance of the main mixing head and the auxiliary mixing head to be less than 0. The equipment for mixing friction welding by dual-shoulders comprises a main shaft and a main shaft shoulder, wherein the main shaft shoulder is arranged on the main shaft, the lower part of the main shaft shoulder is provided with the main mixing head; and also symmetrically comprises a bottom main shaft and a bottom shaft shoulder, wherein the bottom main shaft shoulder is arranged on the bottom main shaft, and the lower part of the bottom shaft shoulder is provided with the auxiliary mixing head. The method and the equipment are suitable for the welding of non-ferrous metals such as copper, aluminium, magnesium and the like with low melting point, can also be suitable for the welding of ferrous metals with high melting point such as steel, and the like, have good welding quality and lead the mixing head not easy to be broken.