The invention discloses a Nylanthrene acid dye printing technology for an elastic nylon swimsuit. The technological process comprises steps of printing, steaming, detergent washing, color fixing and dehydration drying. The produced nylon/spandex warp knitted printed fabric has high fineness, high color fastness, bright color and good elasticity; the Nylanthrene-series acidic printing agent is utilized to print elastic nylon swimsuit fabric, the quality, technological tolerance and the like of a finished product are excellent, and accordingly, the export requirement of top-grade elastic nylon printed fabric can be met.