Abstract: The rock failure process analysis software, RFPA^2D, is used to carry on numerical simulation study of single crack rock of rock specimens in different distributions under uniaxial compression in the failure process. The results show that the rock specimen failure experiences fracture pressure, micro-crack initiation and propagation and final fracture damage of several stages; the mechanics properties of the intact rock specimen is significantly higher than that of single fracture rock specimens. With the increase of crack length, peak strength of rock specimen decreases gradually; according to its lower trend, we fit out the fitting function of peak intensity which decreases with increment of crack length; the function shows that both are negative exponent relationship; and with the increase of crack dip, it presents a trend of increase with the decrease of the first peak intensity; when fissure dip is about 45° , the strength of rock specimen is the minimum value. The smaller of crack length or the bigger of rock specimen dip, the influence of that on the mechanical properties of rock specimen and crack propagation is not obvious; its extension form is similar to complete rock specimen.