For the alternatively soft and hard interbedded rock mass of JinPing HydroJunction project, three failure modes of rock samples under uniaxial compression stress are analyzed based on laboratory experiments, and the influence of dip angle, quantity, distribution and volume ratio of weak intercalations on the deformation property, strength characteristics and failure mechanism of rock mass are discussed by the numerical simulation. The results show that the failure of soft and hard interbedded rock mass of JinPing follows the multicrack splitting mode of uniaxial compression failure. For the case of gentle dip angle, the failure of layered rock mass is controlled by the property of rock mass itself, while for the case of large dip angle, the influence of weak intercalations is the dominant factor. Besides, the number of weak intercalations has no significant effect on the "U" type strength characteristics of layered rock mass, but with the increase of weak intercalations, minimum value of failure load tends to move forward. With the increase of the volume ratio of the weak intercalation, the failure loading totally shows a downward trend, and when the volume ratio of weak intercalation is close in rock samples, the effect of increasing weak intercalation on the decrease of failure load is positively related to the dip angle of weak intercalations. At last, it can also be found that the increase of weak intercalations has no effect on the strength if the rock layer is horizontal.