The invention discloses a combined machine base applied to a large Raymond mill. The combined machine base applied to the large Raymond mill comprises a machine base body fixed to a concrete foundation and a mill ring arranged in the machine base body. A mill air inlet passage is arranged outside the machine base body, the longitudinal section of the concrete foundation is approximately of a U shape, the lateral wall of the concrete foundation is of a step structure, and the main machine base body with the mill ring inside is fixedly arranged on the bottom wall of the concrete foundation. The inner edges of reinforcing plates with the outer edges fixed to the step surface of the lateral wall of the concrete foundation are fixedly connected with the lateral wall of the main machine base body. A traditional integrated machine base for the Raymond mill is divided into the main machine base body and the reinforcing plates fixedly connected with the side of the main machine base body, so that the problems of over-width and overweight of the Raymond mill during production and conveying are resolved. The concrete foundation fixedly provided with the machine base is prefabricated into a foundation with the air passage. When the specification of the Raymond mill is increased, the problems that a volute is too large in size and can not be conveyed easily are resolved. Besides, the main machine base body, the reinforcing plates and the concrete foundation are firmly connected into a whole through foundation bolts fixed in grouting holes, and the rigidity of the machine base of the Raymond mill is increased.