The invention relates to a servo-control hydraulic excitation system for a high-speed rail track roadbed test. The technical scheme of the invention is as follows: the oil press port of an oil pump (11) is respectively communicated with the P port of a servo valve (4) and the P port of a first magnetic exchange valve (6) through a first check valve (8) and a first filter (7); the A port and B port of the servo valve (4) are respectively correspondingly communicated with two working oil ports (26,29) of a dynamic pressure cavity (38) of a twin-stage servo hydraulic cylinder (2); the A port of the first magnetic exchange valve (6) is communicated with the oil inlet of a second check valve (5), the oil outlet of the second check valve (5) is respectively communicated with a second working oil port (24) of a static pressure cavity (45) of the twin-stage servo hydraulic cylinder (2), the A port of an electromagnetic ball valve (16) and an accumulator (3); and the working end of the twin-stage servo hydraulic cylinder (2) is connected with an excitation disc (17), and a right end cap (30) of the twin-stage servo hydraulic cylinder (2) is connected with a hydraulic excavator used for test. The servo-control hydraulic excitation system provided by the invention has the advantages of good dynamic response, small hydraulic system flow and good simulation effect, and meets the requirements of high excitation frequency and high exciting force simultaneously.