Abstract: Stereo light microscope (SLM) is used to reconstruct the 3D shape. The two sub-systems of SLM are symmetry, generating images with slight difference between themselves, and the matching of images plays an important role to guarantee the precision of reconstruction. Using different parameter series, a novel vision model is formulated to transfer the microscopic objects from two-dimensional image space to three-dimensional object space, and the concept of weak disparity is introduced to describe the coherence of microscopic stereo images. Using the vision model, the average reconstruction errors in experiments were 0.74%, 1.98% and 6.66% in X, Y and Z direction of object space respectively. The proposed model was tested both on planar sample and curved surface sample.