The invention relates to a
polyamide 6 POY / FDY composite fibre and a preparation method adopting a
spinning-interlacing one-step process. According to the preparation method,
polyamide 6 dry slices are input in a screw rod, heated, melted and filtered, and then enter a
spinning manifold, a
spinning melt is extruded from two metering pumps, a spinning
assembly and the micropores of two spinneret plate, cooled by an annealing annular device and an annular blowing cooling device, and cured to form two bundles of yarns, and one bundle of the yarns is subjected to
nozzle oiling, pre-networking, stretching and heat-setting between a first stretching roll group and a second stretching roll group, and a third
yarn guide disc to obtain FDY; the other bundle of the yarns is subjected to
nozzle oiling, and a
yarn guide winding
system device which is arranged in parallel to obtain POY; the FDY and the POY are input in a
yarn combiner and interlacing nozzles simultaneously, and subjected to compounding and winding forming to prepare the
polyamide 6 POY / FDY composite fibre. The polyamide 6 POY / FDY composite fibre and the preparation method have the features of fast
processing speed, high yield, low production cost, and
energy conservation and emission reduction; the provided product is good in interlacing degree uniformity and stability, and good in
dyeing effect.