Sodium ion batteries have become the successor of lithium ion batteries due to their advantages of environmental friendliness and abundant reserves，and have great application potential in energy storage materials.In view of the problems of unstable structure and poor cycle stability of manganese-based cathode materials for sodium ion batteries，Na_0.7Fe _x Mn_（1-x）O₂（0<x<1） manganese-based cathode materials were prepared by sol-gel method.The effects of n（Fe）/n（Mn） molar ratio on the microstructure and electrochemical properties of Na_0.7Fe _x Mn_（1-x）O₂ materials were investigated.The results showed that the doping of iron stabilized the P2 phase crystal form of the material and increased the sodium layer spacing.The P2-phase layered cathode materials of Na_0.7Fe_0.2Mn_0.8O₂ and Na_0.7Fe_0.35Mn_0.65O₂ were synthesized.The synthesized two materials of Na_0.7Fe_0.2Mn_0.8O₂ and Na_0.7Fe_0.35Mn_0.65O₂ had charge/discharge specific capacities of 88.54，63.73 mA·h/g and 74.02，49.01 mA·h/g in the first cycle.After 100 cycles，the charge/discharge specific capacities were 51.94，51.36 mA·h/g and 52.15，51.59 mA·h/g，respectively，and the cycle efficiencies were 58.01% and 69.7%，respectively，showing good capacity retention and cycle performance.In terms of rate，the charge and discharge specific capacity of the two materials could still reach 113.82，110.25 mA·h/g and 51.75，51.11 mA·h/g when the two materials were charged at 2C high current and recycled to 0.5C rate.Both materials showed good cycle rate performance.In general，the performance of Na_0.7Fe_0.2Mn_0.8O₂ was more excellent.