In recent years, flexible electronics is an emerging and promising technology for next generation of optoelectronic devices. The study of new inexpensive, flexible and lightweight electrode materials has triggered a gold rush. Herein, hierarchical porous CoO nanosheets arrays/carbon cloth composites successfully synthesized were using a hydrothermal reaction followed by calcination. The three-dimensional network structure can accommodate large mechanical strains by providing the gaps to alleviate volume change. The porous structure can improve the specific surface area of the active substance CoO, which is conducive to the improvement of lithium storage capacity of electrode materials. When investigated as flexible anode for lithium-ion batteries, the CoO porous nanosheets array/carbon cloth materials achieve an initial charge capacity of 1 862.8 mAh·cm-2 with coulombic efficiency of 87.8% at constant current of 100 mA·cm-2. The reversible capacity is 1 428.9 mAh·cm-2 after 100 cycles at current density of 700 mA·cm-2. And it is capable to retain a capacity of 1 353.8 mAh·cm-2 even at current density of 1 000 mA·cm-2. The excellent electrochemical performance of the composites could be attributed to the unique morphology, structure of the CoO porous nanosheets, as well as directly grown on current collector. Thus, this work introduces an easy and economic method for fabrication CoO porous nanosheets array/carbon cloth materials for high-performance flexible lithium ion battery.