To simplify the design process of automatic transmission solenoid valve control algorithm, a development process of modularized and universal control algorithm was present. Taking continuously variable transmission system line pressure valve as an example, control algorithm development process was described. Steady-state characteristics, step-pulse respond characteristics and lag characteristics of solenoid valve were tested. Based on these characteristics, open-loop control table, closed-control algorithm and lag compensation model were designed and made up modularized and universal compound control algorithm. Compared to error as the single input in normal control algorithms,the error and target value were taken as the input parameters and system information was used more effectively in the proposed algorithm.According to the experimental results, the control accuracy and dynamic property of the proposed algorithm are proved.