The invention provides a packer testing apparatus. The packer testing apparatus comprises a simulation branch pipe with extendable lengthwise, a first channel which is penetrates through the simulation branch pipe in the lengthwise extension direction and is arranged in the simulation branch pipe, a pipe body which is arranged in the first channel, a packer which sleeves the pipe body, and a rotation mechanism which is arranged at one end, being close to the pipe body, of the simulation branch pipe, wherein the rotation mechanism comprises a clamping device and a rotation device; the clamping device includes a frame at the outside of the pipe body, and a clamping body which is connected with the frame; a clamping part is arranged at one side, facing the pipe body, of the clamping body; the clamping body can move toward the direction being close to the pipe body so as to enable the clamping part to abut against the outer wall of the pipe body; and the rotation device includes a rotation body which is connected with the frame, and a driving body which drives the rotation body to rotate. The packer testing apparatus is suitable for a packer which needs rotation during the process for set detection.