The embodiments of the application provide an electrode assembly and a manufacturing method and manufacturing system therefor, a battery cell and a battery. The electrode assembly includes a negative pole piece and a positive pole piece, the negative pole piece and the positive pole piece are wound to form a winding structure including a bending region and a straight region. Both the negative pole piece and the positive pole piece include a plurality of bent portions located in the bent area and a plurality of straight portions located in the straight area. At least one of the bent portions of the positive pole piece is a first bent portion, and/or at least one of the bent portions of the negative pole piece is a second bent portion.