The invention relates to the technical field of keyboard shaft body processing, in particular to a rotary disc type automatic assembly device for a keyboard shaft body. The assembly device comprises ahexagonal processing table, and rotary discs, a shaft bottom feeding mechanism, a spring tool mechanism, an elastic support tool mechanism, a connector tool mechanism, a shaft cap tool mechanism anda discharging mechanism which are mounted on the hexagonal processing table separately, wherein the top edges of the rotary discs are provided with workpiece positioning grooves corresponding to the shaft bottom feeding mechanism, the spring tool mechanism, the elastic support tool mechanism, the connector tool mechanism, the shaft cap tool mechanism and the discharging mechanism, and each of theshaft bottom feeding mechanism, the spring tool mechanism, the elastic support tool mechanism, the connector tool mechanism, the shaft cap tool mechanism and the discharging mechanism comprises a clamping jaw capable of lifting and linearly moving between each material box and the corresponding rotary disc. According to the technical scheme, the problems that during mass production, a large amountof manpower is needed for operation, and the parts are prone to be damaged by manual operation; and tooling can be automatically performed, and the efficiency and the tooling quality are improved.