The present invention discloses a method for fabricating a porous spherical iron-based alloy powder, a powder thereof and a sintered body thereof. The method comprises steps: mixing an iron oxide powder and an alloying powder to form a mixed powder; spray-granulating the mixed powder to form a spherical spray-granulated powder; and placing the spherical spray-granulated powder in a reducing environment and heating it to a temperature of lower than 700° C. to obtain a porous spherical iron-based alloy powder having high flowability, high compressibility, superior sinterability and low cost.