<p>From the perspective of the composition and the microstructure, the structure-activity relationship between the mechanical properties and the crushing rate of the fracturing proppants are revealed, in order to provide a theoretical basis for the optimization, quality control, and mechanical performance influence mechanism of quartz sand fracturing proppants. The structure-activity relationship between the compositions and microstructures of the quartz sand fracturing proppants with different specifications, like mesh size, from the same production area and their mechanical properties was studied through using the method of controlling the single variable. The elemental compositions, phase compositions, and microstructures of the samples were characterized by the X-ray fluorescence spectroscopy (XRF), X-ray diffraction (XRD), and scanning electron microscopy (SEM), respectively. The elemental compositions and the phase compositions of the samples are the reasons for the influence on hardness, toughness and fracture ratios. The grain size and pore size of the samples determine the influence mechanism on the density, hardness, toughness and crushing rate. The content of Al₂O₃ determines the mechanical properties of the samples, and the MgAl₂O₄ can help to enhance the mechanical properties. The nano grain size, high density and network-like micromorphology are the significant factors, which lead to high mechanical properties of the samples.</p>