The invention discloses an integrated main speed reducer assembly with an oil throwing blade and relates to a main speed reducer assembly. The integrated main speed reducer assembly comprises an integrated shell, a main speed reducer, an interaxial differential and an inter-wheel differential; the inter-wheel differential comprises a differential shell and a differential, and the differential shell is also connected with the oil throwing blade; the oil throwing blade is of an approximately 7-shaped structure formed by vertically connecting an end surface A and an end surface B, the end surface A of the oil throwing blade is jointed with the end surface of the differential shell, and a connecting hole connected with the differential shell is formed in the end surface A; and the end surface B is jointed with the excircle surface of the differential shell, and the part where the end surface B is jointed with the excircle surface of the differential shell outwards warps to form an edge for scraping and throwing oil. By using the integrated main speed reducer assembly, a rear half axle gear bearing and a tandem axle bearing are sufficiently lubricated, bearing faults such as early wear and ablation as well as tandem axle breakage, tooth beating and tooth jumping can be avoided, and the aims of reducing noise and faults and prolonging the service life are achieved; and the integrated main speed reducer assembly is simple in structure, low in cost and easy to popularize and use.