High-strength lightweight aggregate concrete (HSLAC) with high-strength, light-weight and good frost resisting property and impermeability has the better application prospect, but its low modulus leads to brittle failure. A large number of domestic and abroad shear test data of lightweight aggregate concrete beams were collected, and through the strength grade LC40 divided the test specimens into the normal strength lightweight aggregate concrete (LAC) beams and HSLAC beams. The paper combined the national specification recommended method with the typical statistical model to calculate the carrying capacity of beams, and also presents their comparison with experiment results. Research shows that the shear bearing capacity of LAC beams is lower than the normal weight concrete beams with same strength level, and the increased range of shear bearing capacity of LAC beams is decreased with the increase of concrete strength. The reasonable reduced concrete strength coefficients should be proposed to be used in the design specification according to the different intensity.