Novel shut-off plug for multiple-stage cementing device

The utility model discloses a novel shut-off plug for a multiple-stage cementing device and relates to oil downhole equipment. The novel shut-off plug comprises a hollow main plug body, a sealing ball, an overflowing cover and a rubber plug body. The overflowing cover is mounted at the position of the opening at the upper end of the main plug body, an inner cavity communicated with the main plug body and a through hole formed outside the main plug body are arranged in the overflowing cover, the sealing ball is arranged in the inner cavity of the main plug body, the diameter of the sealing ball is smaller than that of the inner cavity of the main plug body, the diameter of the sealing ball is larger than the maximum diameter of a tapered hole in the lower end of the main plug body, a plurality of grooves used for fixed mounting of the rubber plug body are arranged in the outer wall of the main plug body, a step protruding outwards is arranged at the lower end of the main plug body, one groove used for fixed mounting of the rubber plug body is arranged in the upper end face of the step, and the rubber plug body made of rubber is mounted on the main plug body. The novel shut-off plug is reasonable in structure, and the situation that the inner sleeve of the multiple-stage cementing device cannot fall to the downhole is effectively avoided.