The invention discloses a method and device for evaluating the fracturing fluid flowback capacity of a shale staged fracturing horizontal well and belongs to the field of shale gas development. The method includes the steps of obtaining a shale core, forming multiple groups of fracturing seam nets on the shale core, injecting gas in the shale core to obtain the gas-saturated shale core, recording the volume of the injected gas, injecting fracturing fluid in the gas-saturated shale core to obtain the fracturing fluid saturated shale core, recording the volume of the fracturing fluid, conducting flowback test on the fracturing fluid saturated shale core, recording the volume of the discharged fracturing fluid and the volume of the discharged gas, and calculating a flowback capacity evaluation index. The method can be used for the study of the fracturing fluid flowback capacity of the shale staged fracturing horizontal well through an indoor similar physical simulation method and can provide a scientific basis for improving shale reservoir fracturing and rebuilding effects and improving shale gas-well production, and formulation of a reasonable shale staged fracturing horizontal well discharge and mining system is easily achieved.