An electric drive gearbox assembly with stepped hole positioning is disclosed. Specifically, the electric drive gearbox assembly comprises a first housing (1), a second housing (2) and a positioning pin (3). The first housing (1) is provided with a first positioning hole (4) on its connecting surface. The second housing (2) is provided with a second positioning hole (5) corresponding to the first positioning hole (4). The first housing (1) and the second housing (2) are positioned and connected through the first positioning hole (4), the second positioning hole (5) and the positioning pin (3). The first positioning hole (4) and/or the second positioning hole (5) are stepped holes. The stepped hole comprises a guiding section (4-1) close to an open end of the stepped hole and an engaging section (4-2) far away from the open end of the stepped hole. An aperture of the guiding section (4-1) is larger than an aperture of the engaging section (4-2). The guiding section (4-1) is used to guide the positioning pin (3) into the engaging section (4-2). In the electric drive gearbox assembly, the first housing (1) can be pre-positioned when assembled with the second housing (2), and the first housing (1) can be radially adjusted relative to the second housing (2) during pre-positioning, so as to facilitate the positioning and assembly of the first housing (1) and the second housing (2), and promote automated and batch assembly of the electric drive assembly.