Based　on　the　similarity　principle　and　the　conservation　of　mass,　the　microscopic　fraction　disintegration　and　macro　distribution　of　rock　particles　are　discussed　separately,　and　the　correlation　fractal　dimension　calculation　formula　about　rock　disintegration　is　also　presented.　On　this　basis,　the　fractal　evolution　law　of　clay　rock　disintegration　under　different　pH　conditions　is　investigated.　The　results　show　that,　the　smaller　the　pH　value,　the　greater　the　fractal　dimensions　in　the　preliminary　stage　and　the　fewer　the　cycle　times　to　obtain　the　stable　fractal　dimension.　In　addition,　the　acid　solution　accelerates　the　growth　of　particle　fractal　dimension,　but　the　alkaline　solution　plays　a　role　of　reverse.　It　needs　more　cycle　times　that　the　fractal　dimension　curves　become　stable　in　the　alkaline　conditions.　However,　the　fractal　dimension　under　different　pH　conditions　should　tend　to　be　equal　ultimately.