The utility model relates to a metalaxyl microcapsule of prevention and cure bacco balck shank, its characterized in that: the microcapsule is spherical, comprises at the glutaraldehyde crosslinked chitosan shell (2) outside the metalaxyl powder inner core metalaxyl powder inner core (1) and cladding. The utility model discloses the dough stability is strong, the lasting period is long, can reduce bacco balck shank fungus and produce the disease resistance to the resistance to drugs of metalaxyl and induced cigarette trunk, has the characteristics of high efficiency, slowly-releasing, low toxicity and low-residual simultaneously, has good prevention effect to the bacco balck shank.