Double network gel is well known for its extraordinarily high toughness and stretchability. However, compared to many soft biological tissues such as articular cartilage and tendon, both strength and stiffness of double network gel are significantly lower, which greatly limits its further applications. In this article, to improve mechanical properties of double network gel, we embed a small weight percentage of aligned electrospun polymer nanofibers into double network gel matrix to make a sandwich-like double network gel composite. Mechanical tests conducted by us show that polymer nanofiber reinforced double network gel composite has much higher strength and stiffness, while maintaining its good transparency. (C) 2016 Elsevier Ltd. All rights reserved.