The invention provides a rock ground stress detection method and system. The detection method comprises the following steps of determining the detection range on the circumference of a rock core to be detected; sequentially sending out a detection signal on each detection path in the detection range, wherein the detection path is the diameter of the circumference; determining the wave velocity of the detection signal in each detection path, and determining the detection paths corresponding to the minimum wave speed and the maximum wave speed of the detection signal in each detection path; respectively performing rock sample drilling operation on the detection paths corresponding to the minimum wave speed and the maximum wave speed; and detecting the maximum pressure-resistant intensity of a drilled rock sample. The rock ground stress detection method provided by the invention has the advantages that under the condition of accurately detecting the rock ground stress, the operation process is simplified; the detection efficiency is improved; and the detection cost is reduced. The invention also provides a rock ground stress detection system.