Provided is a method of manufacturing a high strength steel sheet having excellent workability. The method includes: providing a cold-rolled steel sheet including, by wt %, C: 0.25 to 0.75%, Si: 4.0% or less, Mn: 0.9 to 5.0%, Al: 5.0% or less, P: 0.15% or less, S: 0.03% or less, N: 0.03% or less, a balance of Fe and unavoidable impurities; primary heating the cold-rolled steel sheet, and primary holding the cold-rolled steel sheet; primary cooling the cold-rolled steel sheet; secondary cooling the cold-rolled steel sheet, and secondary holding the cold-rolled steel sheet; tertiary cooling the cold-rolled steel sheet; secondary heating the cold-rolled steel sheet; quaternary cooling the cold-rolled steel sheet, and quaternary holding the cold-rolled steel sheet; and fifth cooling the cold-rolled steel sheet to room temperature.