Offshore oil-drilling risers have large length-to-diameter ratios and thin walls. The effect of residual stress is often neglected in the dynamic test on the vertical bearing capacity of risers, which leads to low accuracy of results. Based on a practical project, field dynamic test and wave fitting method were adopted to calculate the bearing capacity of risers. The dynamic characteristics of a riser-soil system and mechanism of residual stress generation and action under continuous hammering were analyzed, and the analysis method of residual stress was presented. Calculation and comparative analysis of bearing capacity, compressive stress, and tensile stress were performed, and the calculation results considering residual stress reflect well the actual stress state of the riser-soil system and effectively correct the error caused by the overestimation of upper soil resistance and underestimation of lower soil resistance, and the accuracy of bearing capacity and stress distribution can be improved. The results show that the bearing capacity of risers considering residual stress is slightly higher than those without residual stress. Compressive stress is lower in the upper part and higher in the lower part of risers than that without considering residual stress, and the result on tensile stress is opposite that of compressive stress. Research results have practical importance in the safe application of risers in offshore oil-drilling engineering.