As one of the promising and extensively studied alloy semiconductors, the optoelectronic properties of Si1-xGex alloys have been well studied, but fundamental electromagnetic (EM) properties are rarely explored and discussed. In this work, the EM excitations of magnetic multipoles and toroidal dipoles in Si1-xGex based permittivity-asymmetric metasurface at near-infrared spectral region are investigated. Multiple Fano resonances (FRs) occur in the structure, and the formation mechanisms of resonance excitations are analyzed in detail combining theory with EM field distributions. In addition, the proposed metasurface is also investigated for its potential as a refractive index sensor due to its finer spectral property. It is hoped that our work will help to understand the EM properties of Si1-xGex alloys and find its potential applications in optics, such as refractive index sensing. The results obtained here provide fundamental insights into the exploration of EM excitations of Si1-xGex alloys.