The combination of wire arc additive manufacturing (WAAM) technology with traditional manufacturing process providesa promising method for fabricating the large and complex parts with the advantages of high performance, time-saving, lowcost and high material utilization. In order to acquire the optimal hybrid manufacturing process, the comparative study offlow behaviors and microstructure evolution of wrought and WAAMed ultrahigh-strength (UHS) steels is carried out underthe temperatures of 920–1160 ℃ and strain rates of 0.01–10 s−1 . The results show that the coarse prior austenite columnargrains and carbides in the initial microstructure of the WAAMed UHS steel contribute to the higher flow stress and slowerdynamic recrystallization (DRX) kinetics during hot deformation as compared to the wrought UHS steel. The hot activationenergy under the peak stress of the wrought and WAAMed UHS steels is estimated to be 332.3 kJ/mol and 374.1 kJ/mol,respectively. On the basis of the hot processing maps, the common optimal processing window for WAAMed and wroughtUHS steels is determined as the temperatures of 1060–1160 oC and strain rates of 0.08–0.66 s−1 . Under these deformationparameters, the microstructures of WAAMed and wrought UHS steels consist of fine DRXed grains, and the DRX behaviorsare both dominated by the discontinuous DRX and continuous DRX mechanisms.