Ground stress testing device and testing method

The invention discloses a ground stress testing device and a testing method. The ground stress testing device comprises a pressurizing water injection device, a drill rod, an upper packer, a rotatable guide plate, an electronic compass and a lower packer, one end of the drill rod is communicated with the pressurized water injection device, the other end of the drill rod is communicated with a water inlet of the channel change-over valve, and the channel change-over valve further comprises a first water outlet passage and a second water outlet passage which are selectively communicated with the water inlet; the upper packer is communicated with the first water outlet passage; the rotatable flow guide plate comprises a central flow guide pipe rotationally arranged between the upper packer and the lower packer and flow guide blades arranged on the central flow guide pipe, flow guide seams are formed in the flow guide blades, and when water flow enters the central flow guide pipe and is sprayed out through the fl