The effects of different strain ways (tension, bend and compression) on the formation and propagation of micro-cracks and critical current of Bi-2223/Ag superconducting tapes were studied. The results show an obviously differences on the critical strain values of the tapes under various strain ways are presented. Moreover, the propagation ways of the micro-cracks in the superconductor filaments are quite different: the micro-cracks form at the surface and then spread to the center in the bending samples, while the formation of the cracks are at random in the tensile samples. The formation mechanism of micro-cracks in the filaments was mainly discussed. It is found that multitudes of transversal and rolling direction micro-cracks form under tensile deformation. However, predominantly rolling direction micro-cracks and little transversal micro-cracks are found under compressive deformation. It is the interaction of the above mentioned two types of the micro-cracks that leads the degradation of Ic of the tapes.