Direct drive type volume control electrohydraulic servo hydraulic system for hydraulic press

The invention provides a direct drive type volume control electrohydraulic servo hydraulic system for a hydraulic press. Two ends of a hydraulic pump are respectively connected with a low-voltage electromagnetic reversing valve group and a high-voltage electromagnetic reversing valve group; a main oil tank is connected with two ends of the hydraulic pump through two oil compensating valves; a main cylinder and an ejecting cylinder are isolated through the low-voltage electromagnetic reversing valve group and the high-voltage electromagnetic reversing valve group, and a main cylinder loop and an ejecting cylinder loop are formed; oil is supplied by the hydraulic pump; a rodless cavity of the main cylinder is connected with the high-voltage electromagnetic reversing valve group and a prefill valve, the prefill valve is connected with a prefill barrel, and the prefill barrel is connected with the main oil tank through a high-position oil pipe; a rod cavity of the main cylinder is connected with the low-voltage e