Taiwanese quinoa (Chenopodium formosanum), an herbaceous plant endemic to Taiwan, is highly nutritious and has the potential to become an important future food crop. Its antioxidant properties also make it valuable in the development of health foods and pharmaceuticals, such as for stabilizing blood sugar and protecting cardiovascular health. To maintain growth under salt stress, plants may develop salt storage structures to excrete excess salts from their tissues, or accumulate osmotic adjustment substances to stabilize cellular osmotic pressure, thereby maintaining turgor and relative water content. In addition, plants can rely on their internal antioxidant systems to eliminate reactive oxygen species generated under salt stress. This study focuses on three different varieties of C. formosanum—red, yellow, and orange—to investigate the effects of salt stress on their growth and explore potential mechanisms, in response to challenges posed by climate change and soil salinization on agricultural production.