The invention discloses a scroll spring assembly tool, comprising a rotation shaft, a top shaft, a recovery spring, a cam, a pin shaft and an operation rod; wherein, the rotation shaft is internally provided with a container and the center of the bottom surface thereof is provided with a clamping trough; the top shaft is inserted in the container in an axially movable way; the lower end of the topshaft can be exposed out of the bottom surface of the rotation shaft; the recovery spring is arranged between the top shaft and the rotation shaft; the cam is rotatablely sheathed on the external surface of the rotation shaft; the pin shaft is fixed on the bottom surface of the cam and extends downwards; the operation rod is connected with the external wheel edge of the cam. The scroll spring assembly tool can lead the scroll spring to reach the needed elastic deformation easily; after the workpiece is placed to corresponding position, the top shaft can lead the scroll spring to disengage theassembly tool and automatically combines with the workpiece during the elastic recovery process, thus completing the assembly; therefore, the invention has the advantages of simple structure and convenient use, greatly improves the assembly efficiency of the scroll spring and reduces the labor intensity.