Micro stereo lithography is a kind of technology utilizing the solidified effect that photo curable polymer will appear under ultraviolet (UV) laser exposure. It is widely used in three-dimensional (3D) micro fabrication. We get the experimental values of a pair of UV laser curing coefficients, absorption coefficient and critical curing energy, of curable resin by fitting the calculation results of the Gaussian beam theory and experimental curing results. The theoretical relation between the curing unit’s shape and the exposure features of time and intensity of convergent Gaussian beam is presented. The calculation and experimental results of curing unit under different conditions agree well with each other. This research offers a steady base for further research about the improvement of resolution.