The present disclosure provides a stretchable display substrate and a stretchable display device. The stretchable display substrate includes a substrate having a wiring region and a display region along a first direction, the display region including a plurality of display units and a plurality of connecting units, the plurality of display units being spaced apart from each other and arranged in an array; each of the hollow structures having a first extending portion extending along a second direction, wherein the display region includes a first transition region close to the wiring region and a central region away from the wiring region, and the first length of the first extending portion of each of the hollow structures in the transition region is not greater than the first length of the first extending portion of each of the hollow structures in the central region.