To study the relationship of thickness-to-diameter ratios and loading ratios two factors on Maokou limestone tensile strength, had a series of Brazil tests under small arc symmetrical loading. Using finite difference software ANSYS to simulate Brazilian Splitting test, and analysis equivalent stress distribution rules in different thickness to diameter ratio disc specimens under different loading rate, tests show that: rock tensile strength is linear increasing with the increase of loading rate, Brazilian Splitting Strength reduce in cubic function with the increase of thickness-to-diameter ratios.3D numerical results show that: the closer the center of the disc of the sample ends, the greater the value of the equivalent stress; in addition to individual points of stress concentration, equivalent stress value increased with the increase of loading rate at the center of the ends, the first fracture starting point is at the center of the ends. Based on which test results of Brazil split was revised to get a more real tensile strength considering effects of loading rate and thickness-to-diameter ratios.