Abstract: Tensile strength of coal measures sandstone has mineral particle size effect by the analysis of existing field test results. We simulated coal measures sandstone split disk by different grain sizes of quartz sand and cement paste, and investigated change laws of sample density under different quartz particle size, and studied the tensile strength characteristics of split disks. The results show that load-displacement curves of split disks are divided into three stages as a whole: compaction, linear change and fast falling after peak. With the increase of quartz sand size, the density and tensile strength of split disk increases gradually, which presents the strengthening characteristics.