The market for printed and flexible electronics, key attributes for internet of things, is estimated to reach $45 billion by 2016 and paper-based electronics shows great potential to meet this increasing demand due to its popularity, flexibility, low cost, mass productivity, disposability, and ease of processing. However, conventional flexible devices made of paper and plastic substrates are expected to have thermal issues due to their poor thermal conductivity. In this work, we demonstrated flexible solar-blind deep-ultraviolet (DUV) sensors based on 2D boron nitride nanosheets (BNNSs) composited paper with good detectivity (up to 8.05 × 10¹⁰ cm Hz^1/2/W), fast recovery time (down to 0.393 s), great thermal stability (146 W/m K, 3-order-of-magnitude larger than conventional flexible substrates), high working temperature (up to 200 ^oC), excellent flexibility and bending durability (showing repeatable ON/OFF switching during 200-time bending cycles). This shows great potential to be a key component to solve thermal problems and fully activate flexible electronics for meeting the demand of internet of things.