The invention discloses iron-based pre-alloyed powder prepared through recycled nickel and cobalt and a preparing method. The powder is composed of iron, nickel, copper, cobalt and chromium according to a certain proportion. The method comprises the steps of firstly, component detection, wherein an artificial diamond wastewater chemical electrolytic recovery waste nickel and cobalt plate is analyzed, and the content of nickel and cobalt is determined; secondly, material preparing, wherein according to the detected nickel and cobalt content result, iron, nickel, copper, cobalt and chromium are calculated, and according to the total weight of graphite powder : metal, graphite powder is prepared; thirdly, water atomization powder making, wherein the prepared metal is placed in an intermediate frequency furnace, nitrogen is used for forming a gas curtain, air is isolated, after the mixed metal is molten, the graphite powder is added, and liquid metal is crushed and atomized into alloy powder through high-pressure water; fourthly, screening blending, wherein the prepared alloy powder is sieved, and is sufficiently blended in a mixing machine, and the pre-alloyed powder is obtained. The method is reasonable in formula, simple in production technology, low in powder oxygen content, uniform in granularity and good in cold pressing molding, and has the wide application prospect in diamond cutters and tool structural parts.