The invention provides an arrangement scheme for a convertor transformer square and belongs to the field of high-voltage direct current transmission. The scheme provided by the invention is designed for optimizing the arrangement of the convertor transformer square for an extra-high voltage direct current project and reducing the quantity of convertor transformer conveying rails. The technical scheme adopted by the invention is as follows: five firewalls of a high-end valve hall of a convertor station and five of firewalls of a low-end valve hall are equidistantly coaxially arranged, and meanwhile, the relative positions of the convertor transformers of the high-end and low-end valve halls and the firewalls on two sides along the same direction are kept consistent, so that conveying rails can be shared by the convertor transformers corresponding to the high-end and low-end valve halls, so as to achieve the purpose of reducing the quantity of the convertor transformer conveying rails.