A consolidating method of “shell plate” aiming at the existing right-angle mutational steel crane beam is proposed， where a “shell type” steel plate with an arc is welded on both sides of the web at the variable section of the crane beam for fatigue reinforcement. The stress level of fatigue detail is reduced by increasing the stiffness of the web in variable section areas， thus improving its fatigue strength. In this paper， the fatigue performance of a right-angle mutational steel crane beam reinforced with “shell plate” is studied through a scaled fatigue test， the fatigue failure law of the crane beam reinforced with “shell plate” is analyzed， while the fatigue performance of the reinforced crane beam is evaluated. Meanwhile， taking the principal stress of the most dangerous fatigue detail of the reinforced crane beam as the basic parameter， the Sr，p-N fatigue curves of the reinforced crane beam are given. Moreover， the correctness of crack propagation simulation and fatigue life calculation of the crane beam after reinforcement is verified by the experimental results， and the fatigue crack propagation characteristics of the crane beam damage details after the “shell plate” reinforcement are further analyzed. The influence of the variation in thickness and height of the “shell plate” on the reinforcement effect is studied， which provides the reference for the crane beam reinforcement design.