Abstract: To investigate the influence mechanism and law of shear span ratio on the shear resistance and failure mechanism of CFRP (carbon fiber reinforced polymer) strengthened RC (reinforced concrete) shear wall, a three-dimensional numerical model of CFRP-strengthened RC shear wall was established, considering the Hashin damage criterion and the Cohesive model. Firstly, the accuracy of the numerical simulation method was verified by the existing experimental data. Then, the failure modes, shear bearing capacity, and ductility coefficient of CFRP-strengthened RC shear wall under different shear span ratios and CFRP wrapping methods were studied. Further, the influence law of shear span ratio and wrapping method on the CFRP shear contribution and strengthened efficiency were analyzed. The results show that: with the increase in shear span ratio, the shear bearing capacity of CFRP-strengthened RC shear wall decreases, and the CFRP shear contribution and the strengthened efficiency were significantly weakened. Additionally, under the same shear span ratio, RC shear walls strengthened by horizontal strips will improve the efficiency of shear strength by 1.0~3.0 times, and the improved efficiency of ductility coefficient was increased by 0.8~2.4 times, compared with double-sided and full-wrapped strengthened methods.