Abstract: In order to clarify the effect of electrolyte concentration on the electrochemical modification of mudstone,a percolation experimental apparatus for the electrochemical modification of mudstone was developed,and the electrochemical modification experiments of mudstone under different electrolyte concentrations were carried out. The percolation experimental apparatus is composed of a power supply,an ammeter,a voltmeter,a wire,a sample chamber and a slow-release chamber,etc.,by filling the cathode and anode slow-release chamber with different sustained-release materials to block or weaken the corrosion of the extreme pH environment produced by water electrolysis on rock samples and electrodes. Based on the test results of Brazilian splitting,water absorption expansion,resistivity and X-ray diffraction of rock samples,the changes of physical properties such as tensile strength,water absorption,swelling and shrinkage,resistivity and mineral composition of mudstone under electrochemical action were studied,and the correlation of physical properties was discussed. The results show that:①with 0.5 mol/L as the inflection point,the tensile strength decreases at first and then increases with the increase of electrolyte concentration,and the discreteness of the test results increases,while the change trends of water absorption,expansion and resistivity are similar,all increase at first and then decrease with the increase of electrolyte concentration. ②After electrochemical action,the relative content of quartz in rock samples increases monotonously with the increase of electrolyte solution,while calcite decreases monotonously,while muscovite and chlorite change little. ③There is a certain linkage among the physical properties of electrochemically modified rock samples,such as tensile strength,water absorption,expansibility,resistivity and mineral composition:the tensile strength increases linearly with the increase of quartz content and decreases linearly with the increase of calcite content. Water absorption and expansion ratio decrease linearly with the increase of tensile strength,but the relationship between resistivity and tensile strength is difficult to be expressed quantitatively by a specific function.