The flexible strain sensors that integrate optical and electric signals are rather limited, although the flexible sensor community has witnessed increased progresses. Herein, we have fabricated stretchable polymer composites showing both mechanically modulated fluorescence and electric resistance by using polyester elastomer, zinc phthalocyanine (ZnPc) and silver nanowires (Ag NW) as basic components. Specifically, the strain variation in the range of 0-30% and 50-400% can be well correlated with the alternation of electric resistance and red fluorescence of flexible composites, respectively. The present work will open the way for the large-scale fabrication of multi-functional flexible strain sensors. (C) 2018 Elsevier B.V. All rights reserved.