The present invention discloses a method for preparing a PET/PTT parallel complex filament with high self-crimpiness, wherein PET and PTT are sliced, dried and crystallized, and then fused separately and subjected to extrusion molding through a parallel-type spinneret plate; oil is applied after cooling; then level 1-3 drafting and heat setting treatment are adopted; and during drafting, a total drafting rate is controlled to be 3 to 3.5, wherein the level-1 drafting rate is 2.8 to 3.0 at a temperature controlled to be 75 to 80° C., according to the method for preparing the PET/PTT parallel complex filament with high self-crimpiness, methods like multi-level drafting for increasing the drafting rate are adopted, and the effects of improving the fiber strength, moderately lowering the breaking elongation, and greatly improving the self-crimpiness are achieved.