The utility model discloses a waterproof bike saddle cover of stowable belongs to seat cover technical field. Waterproof bike saddle cover of stowable includes seat cover, seat cover skirt section, seat cover rubber band, accomodates the bag, accomodates a bag rubber band, fixed connection cloth ring, nylon rope, key ring, the seat cover adopts waterproof cloth, make with saddle assorted shape, the seat cover rubber band makes the seat cover opening form the elastic expansion mouth, accomodate the bag and adopt the waterproof cloth, sew up inside the seat cover, accomodate a bag rubber band messenger and accomodate a bag opening formation elastic expansion mouth, fixed connection cloth ring adopts the waterproof cloth, sews up in accomodating bag inside, guarantees that the nylon rope passes, the nylon rope is used for connecting key ring and fixed connection cloth ring. The utility model discloses the light is small and exquisite, can hand -carry, and key ring can be connected with cyclic annular article, like key ring, schoolbag zip fastener etc. When raining, can overlap and prevent on the saddle that the rainwater from soaking the saddle. When accomodating, accomodate the seat cover in accomodating the bag, use and collect the convenience, be applicable to various bicycles.