The influence of Fe, Si content and middle annealing process upon cable foil mechanical properties were studied. The production proves that cable foil has fine comprehensive performance targets when Fe is in 0.30% -0.36% and Si in 0.1 1% -0.17%. The middle annealing process can change the strength of cable foil, improve its elon gation, reduce its anisotropy, and it's advantageous to the compound of aluminium foil. It points out that the proper Fe/Si ratio and middle annealing process is a way of improving the mechanical performances of 1145 cable foil.