The evolution and increment characteristics of uniaxial compressive deformation field of limestone sandstone based on the digital speckle correlation method (DSCM) were studied. Based on the deformation field observed by DSCM correlation method, the increment analysis method was used to calculate the increment increment of four indexes, including non-uniformity, displacement, deformation energy density and maximum shear strain under different stress increment conditions, and the evolution characteristics of the rock in the pre-peak and post-peak stages were studied. The results show that: (1) The abrupt starting stresses of non-uniformity, displacement and deformation energy density are consistent. (2) According to the incremental analysis, the energy mainly accumulates before and after the deformation localization starts, and the accumulation velocity of stress around 30 MPa increases first and then decreases, and the abrupt change amplitude of the curve is inversely proportional to the incremental step distance. (3) The evolution law of the non-uniformity index is the same with different stress increment steps, but the larger the step distance, the larger the nonlinear mutation amplitude, and the smaller the mutation starting stress. The incremental evolution of the deformation field under different increment step conditions is a nonlinear fluctuation in the early stage after the peak, and the abrupt change occurs in the vicinity of failure, and the mutation amplitude is proportional to the incremental step length.