To solve the problem that the shearing amount in traditional spatial carrier phase-shift shearography systems is hard to be rapidly, quantitatively, and precisely modulated, this paper proposes a spatial carrier phase-shift shearography system based on a liquid crystal spatial light modulator (LC-SLM). With LC-SLM as a shearing amount modulator, the phase of each tiny liquid crystal unit in the working area of LC-SLM is precisely controlled by electrical addressing, and the phase-shift modulation in the frequency domain is converted into displacement modulation in the spatial domain through the Fourier transform of lens. As a result, the shearing amount can be modulated accurately. An experimental setup is developed to verify the proposed method. The experimental results show that this system can carry out the full-field measurement of interference phase changes caused by object deformation. By writing the periodic fringe images in LC-SLM, this system can modulate the shearing amount and the spatial carrier frequency. Compared with the traditional spatial carrier phase-shift shearography system, the proposed system can quantitatively, accurately, and rapidly modulate the shearing amount.