Protein extraction from soybeans is a vital part of the soy industry. Traditionally, the extraction of soy protein has been done by alkaline extraction and isoelectric precipitation. As technology has advanced, more extraction techniques are superior to this traditional method. In this review, the composition and classification of soy protein are summarized. Next, the current emerging technologies for soy protein extraction are highlighted. Three extraction technologies, namely reverse micellar, enzyme-assisted and membrane ultrafiltration, are reviewed in detail. Finally, the research prospects and trends of soy protein extraction technology are also summarized.