The invention discloses a CM/EPDM blended rubber single-phase etching method and a resolution improving method during rubber blended material microscopic structure expression. The CM phase in CM/EPDM blended rubber is vulcanized through a vulcanization system; the EPDM phase is maintained to be in an unvulcanized state; then, an etching agent is used for etching the EPDM phase in the CM/EPDM blended rubber away from a blending system to form holes; the un-etched CM phase is left; then, volatile solvents are used for extracting the excessive etching agents from the blended rubber; the operation is completed after drying. One phase in the blended rubber is vulcanized to form a reticular structure, so that the stable structure is maintained in the etching process; the erosion by the solvents is avoided; the unvulcanized phase is etched; the observable surface appearance is formed.