Abstract: To monitor the crack damage located at the bolt hole of the metallic bolted-joint structure, based on the Ref. 18, the paper proposed a kind of rosette eddy current sensor with planar and flexible characteristics. Semi-analytical crack perturbation model of rosette eddy current sensors was constructed, and perturbation voltages of sensing channels under the three-dimension structural crack were obtained. Experiments were carried out to validate the model. During the model formulation, the surfaces of the three-dimension structural crack were meshed, and free charge density of each meshed cell center was defined as unknown parameter. According to the boundary condition of free charge and perturbation model assumption, the linear equations containing all unknown parameters were built, and the distribution of free charge density around the structural crack could be acquired via solving linear equations. The crack growth simulation experimental results show that perturbation models of 2A12-T4 aluminum alloy and stainless steel agree relatively well with experiment result under 3 MHz and 6 MHz stimulation frequencies, and perturbation model errors of four sensing channels are within 25 percent.