High-performance solid polymer electrolyte (SPE) has long been desired for the next-generation high energy density and safe rechargeable lithium batteries. A SPE composed of 80 wt％ lithium bis(trifluo-romethanesulfonyl)imide (LiTFSI), 20％ poly(ethylene carbonate) (PEC) and a polyamide (PA) fiber membrane backbone was prepared by solution-casting method. This solid electrolyte exhibits quite high ionic conductivity and lithium ion transference number (t+), and excellent mechanical strength. The as-prepared solid electrolyte shows good wettability to porous electrodes during cycles, which is beneficial to form ionically conductive phase throughout porous electrodes. All-solid-state LiFePO4|Li cells assembled with the as-prepared solid electrolyte deliver a high initial discharge specific capacity of 125.7 mAh·g-1 and good cycling stability at 55 °C (93.4％retention at 1C after 200 cycles), and superior cycle per-formance. Outstanding electrochemical performance can be mainly ascribed to the improved ionic conductivity in the entire porous electrodes due to the good wettability of SPE.