The propagation behavior of love waves is investigated in the layered half-space structure with an imperfect interface. The structure is consisting of an orthotropic elastic layer and a piezoelectric half-space. The imperfect degree of interface is described by the shear-lag model. The surface of the orthotropic layer is assumed to be mechanically free. The wave equations of piezoelectric material and orthotropic material are solved firstly, and then the dispersion equation is derived in an explicit form by boundary condition and interface condition. The numerical examples are provided to show the combined effects of the imperfect interface, the orthotropic degree and the material properties of the piezoelectric layer on the dispersion characteristics. The results show that the velocity of the love waves is decreased with the wakening of the boundary condition. The orthotropic degree and the piezoelectric constant have little effect on the velocity of love waves when the interface is highly imperfect.