A three-dimensional porous scaffold and a preparation method thereof. The three-dimensional porous scaffold comprises a biodegradable multifilament draw-textured yarn on the inside of a tubular knitted fabric made of a biodegradable polymer. The three-dimensional porous scaffold has a porosity formed by the network mesh structure of the tubular knitted fabric and the 10-150 μm pores formed in the biodegradable multifilament draw-textured yarn, while it has a bulkiness of 150-1000% due to the biodegradable multifilament drawn textured yarn inserted in the tubular knitted fabric. Thus, the scaffold has a high degree of interconnection between pores, so that cell culture, cell delivery or drug delivery on the stable three-dimensional scaffold structure is performed in an optimized manner.