The invention discloses an automatic machining device for foundation bolts. The automatic machining device comprises a storage frame, a base, a feeding mechanism, a cutting and bending mechanism, a conveying mechanism, a thread rolling mechanism, a discharging mechanism and a control mechanism. The storage frame cooperates with the feeding mechanism connected with the cutting and bending mechanism. The conveying mechanism comprises a conveying plate, a conveying table and a first motor. The discharging mechanism comprises a second motor, a conveying belt, a conveying plate, a discharging plateand a receiving cylinder. Through cooperation of the feeding mechanism, the cutting and bending mechanism, the conveying mechanism, the thread rolling mechanism and the discharging mechanism, the foundation bolts can be fully-automatically integrally formed, cutting, bending and thread rolling are conveniently, quickly and accurately finished, manual operation is reduced, the work efficiency is improved, the yielding capacity of the foundation bolts can be increased to six tons every day by four persons, the production efficiency is greatly improved, machining process integration is realized,and machining accuracy is ensured.