Previous studies on the impact of crack damage on the mechanical properties of steel primarily focused on sin-gle-crack damage, neglecting the influence of more common multi-crack damage Therefore, to investigate the effects of the randomness and uncertainty of multi-crack length and angle on the mechanical properties of steel, this paper conducts experimental analysis and research on Q355 steel components with asymmetric crack damage. Through projection equivalent transformation, cracks inclined at angle α are transformed into equivalent cracks perpendicular to the loading direction for further analysis. A correction coefficient is introduced to evaluate crack spacing effects on residual ultimate strength. This effectively avoids the drawbacks of traditional methods, such as cumbersome calculation of mechanical responses for inclined cracks and low fitting accuracy. Furthermore, a method for analyzing the residual ultimate strength in the case of asymmetric double cracks is proposed. That maximum computational errors below 4% are achieved by the proposed method is demonstrated by the results, demonstrating high precision. These findings provide theoretical foundations and technical references for subse-quent research, holding significant theoretical value and practical implications for engineering applications.