The invention provides a pile leg folding method for a self-elevating platform. The pile leg folding method comprises a top pile leg section folding step, a main ship body elevating step and a pile leg sectional folding step; in the top pile leg section folding step, top pile leg sections are folded on a main ship body; in the main ship body elevating step, the main ship body is elevated to a preset height, and a support structure is arranged on a berth to support the main ship body; and in the pile leg sectional folding step, the top pile leg sections are elevated by utilizing an elevating device on the main ship body, to-be-folded pile legs are sequentially moved below the top pile leg sections in a sectional manner and are folded. The pile leg folding method is hardly affected by environment and weather conditions, and has little requirement on a hoister; safety of construction work is improved; meanwhile, a construction period can be shortened; and platform construction cost is lowered.