Abstract: The effective mass transfer coefficient of hydrogen ion is an important basic parameter of acid rock reaction kinetics, and it is an essential basic parameter for acid fracturing design of carbonate reservoir. It is usually measured by rotating rock disk instrument or conventional size parallel rock plate flow test, but the rotating rock disk instrument cannot simulate the reaction of acid in the formation, and there is a deviation in the test results of high viscosity liquid. In the parallel plate flow experiment, if the size of rock plate is short, then calculating the hydrogen ion mass transfer coefficient will cause large error by using the difference of the rock plate quality or the difference of acid concentration. In this paper, a new method for measuring H⁺ effective mass transfer coefficient in fractures by large scale linear dynamic displacement is designed. Three-dimensional laser scanning of large size rock plates before and after peracid is carried out, and the acid etching volume of the rock plates is measured, then the acid consumption rate and H⁺ effective mass transfer coefficient are calculated. In this paper, the H⁺ effective mass transfer coefficients of gelling acid and diverting acid in the dolomite of west Sichuan permian Qixia formation are tested, which are between (1.50-2.31)×10^-5 m/s. The results provide key dynamic parameters for fracture simulation, acid fracturing design and acid fracturing effect evaluation.