The invention discloses a rock-soil body tensile detector which comprises a detection assembly and an environmental simulation assembly. The detection assembly comprises a support table, a height adjusting component and a rock-soil body tensile detection mechanism, the height adjusting component is vertically arranged at an end of the support table, and the rock-soil body tensile detection mechanism is horizontally arranged on the upper side of the support table; the environmental simulation assembly comprises a rainwater spray mechanism and a temperature control mechanism, and the rainwater spray mechanism is horizontally fixedly arranged on the height adjusting component at the end of the support table. The rock-soil body tensile detector has the advantages that axial tensile tests can be carried out on to-be-detected soil samples of undisturbed soil or remolded soil under different rain intensity conditions by the rock-soil body tensile detector, the traditional sliding friction modes are replaced with rolling friction, accordingly, the influence of frictional force on the rock-soil body tensile tests can be reduced, and the accuracy of tension characteristic detection on the to-be-detected soil samples can be guaranteed.