Taking Trichodema viride-spent mushroom substrate（SMS）fermentation product as experimental material，this paper studied the effects of combining it with peat，vermiculite by different ratio（V/V） on promoting cucumber seedling growth and controlling efficiency on cucumber root rot．The results
showed that the physiological and chemical properties of treatment T7（ Trichodema viride-SMS fermentation product∶peat∶vermiculite = 1∶1∶1），T9（Trichodema viride-SMS fermentation product∶peat∶vermiculite =2∶1∶1）and T11（Trichodema viride-SMS fermentation product∶peat∶vermiculite = 1∶2∶1）were very near that of the contrast（Trichodema viride-SMS fermentation product∶peat∶vermiculite=0∶2∶1）．Thirty days after inoculation of Fusarium solani，the control efficiency of T7，T9 and T11 treatments on cucumber root rot were 88.56%，78.34%，82.31%，respectively，and were all significantly higher than that of the contrast thiophanate-methyl．In the experiment of nurturing cucumber seedlings，the mixed substrate T7 had the best
performance in terms of plant height，steam diameter，leaf area，chlorophyll content，number of lateral roots，above-ground and underground dry matter weights，root system activities，etc．Their indexes were 117%，127%，171%，99.4%，170%，189%，237% and 125% of the contrast，respectively．Therefore，taking Trichodema viride-SMS fermentation product for cucumber seedling culture had not only good efficiency on stimulating cucumber seedling growth but also better control effect on cucumber root rot．