The invention provides a device for compensating a warp tension based on stereo loom fabric weave. A stereo loom comprises warp beams, warp yarns from the warp beams penetrate through a heald frame to be interwoven with weft yarns through a layering frame so as to form a fabric. The device for compensating the warp tension comprises tension rollers for vertically moving to perform synchronous compensation on warp extension or shrinkage caused by vertical movement of the heald frame and driving devices of the tension rollers. Each warp beam is correspondingly provided with one tension roller, the warp yarns from the warp beams bypass the tension rollers in a U-shaped mode and then penetrate through the heald frame to be interwoven with weft yarns through the layering frame. The invention further provides a method for compensating the warp tension based on the stereo loom fabric weave. The active compensating method is simple in structure and reliable in performance, can very well adapt to weaving of high performance fiber such as poor-elasticity carbon fiber and can meet the compensating requirement that the stereo loom provided with multiple opening and one heald frame needs frequent stroke change, the loom efficiency and fabric quality are improved.