The invention discloses a hydraulic formwork creeping system and a formwork creeping method. The hydraulic formwork creeping system comprises a formwork for casting concrete to form a wall, an outer wall rail and a supporting platform. The supporting platform is arranged on the top of the wall. The formwork is arranged below the supporting platform and connected with the supporting platform. The hydraulic formwork creeping system further comprises a formwork creeping device for driving the formwork to creep, and the formwork creeping device is provided with an inverted hydraulic oil cylinder. The hydraulic formwork creeping system further comprises a first beam and a second beam respectively connected with the hydraulic oil cylinder. The supporting platform, the outer wall rail and the first beam are fixed to form a whole in space. The two ends of the first beam and the two ends of the second beam are respectively fixed to the cast wall, the hydraulic oil cylinder stretches out and draws back to drive the first beam and the second beam to ascend alternately so that the whole formed by the supporting platform, the outer wall rail and the first beam can drive the formwork to ascend along with the ascending of the hydraulic oil cylinder, and formwork creeping can be achieved. According to the hydraulic formwork creeping system and the formwork creeping method, the height of the overall formwork creeping is reduced, the hydraulic formwork creeping system is simple in structure and convenient to implement, and safety construction is facilitated through reduced dead weight.