The invention discloses a horizontal numerical control three-dimensional carving machine which comprises a base, a portal frame, a workpiece clamping device, a transverse moving mechanism, a vertical moving mechanism and a carving tool frame. The workpiece clamping device comprises a fixed beam, a movable beam and a moving and fixing mechanism. A front-back moving mechanism is arranged between the workpiece clamping device and the base, and comprises two slide rails, slide blocks, a driving structure, slide rail waterproof covers and a movable base plate. The slide rails are fixedly arranged on the base. The driving structure is arranged in the middle. The slide blocks are arranged on the two sides, corresponding to the two slide rails, of the movable base plate respectively. The slide blocks are each of a crank structure. One end of each slide block slides on the corresponding slide rail, and the other end of each slide block is fixedly connected with the movable base plate. The slide water waterproof covers cover the two slide rails and cover the ends, correspondingly sliding on the slide rails, of the slide blocks respectively. The carving machine is high in structural weight capacity, stable in structure and smooth and stable in mechanical actions, and factors influencing carving accuracy and carving consistency can be reduced as much as possible.