The electro-hydraulic system has the characteristics of high power density and high load carrying capacity, but it also has the problems of strong nonlinearity, high interference, and difficult parameter determination, which leads to the difficulty of controlling the electro-hydraulic system. To address the above problems, a new model-free sliding mode control (MFSMC) based algorithm is introduced in this study. Firstly, the mathematical model of the hydraulic system is established; then a model-free sliding mode controller is designed; finally, an electrohydraulic position servo control platform based on the model-free sliding mode control algorithm for the valve-controlled cylinder is established, and the experimental results are analyzed and the corresponding conclusions are drawn. The research results show that the established electro-hydraulic position servo system of valve-controlled cylinder based on model-free sliding mode control algorithm is characterized by high control accuracy, fast response and strong robustness.