This article centers its investigation on high-moisture-content solidified lightweight soil in the Binhai New Area of Tianjin. It examines the shear mechanical properties under conditions of significant deformation, supplying pertinent reference values and theoretical foundations for engineering practice. The results demonstrate that the curve for solidified lightweight soil under substantial shear conditions manifests a strain-softening tendency. As normal stress escalates, both peak and residual strength increase while the degree of softening diminishes. The peak strength envelope at varying shear rates forms an upward zigzagging line, with the bending degree of the line augmenting as the rate increases. As the shear rate elevates, the cohesive strength within the peak strength parameters intensifies, the internal friction angle remains constant, and the residual strength parameters remain unaffected by the shear rate. This furnishes theoretical guidance for the applied engineering of blown-cured lightweight soil.