The invention provides a technical scheme of a novel lead delay element cutting device. The device comprises a base, a motor speed reducer, a lead cable, a blade, a blade fixed frame, a lead cable bracket, an upper baffle plate, a lower baffle plate, a tangent length adjuster and a tangent length adjusting rod, wherein the base comprises a blade platform and a cable cutting platform; the blade fixed frame is arranged on the blade platform, and can slide corresponding to the base; one end, near the cable cutting platform, of the blade fixed frame is fixedly connected with the blade, and the other end is connected with the motor speed reducer through a transmission rod; the lead cable bracket, the upper baffle plate and the lower baffle plate are arranged on the cable cutting platform; the lead cable freely drops on the tangent length adjuster after penetrating through the upper baffle plate and the lower baffle plate from the lead cable bracket; the tangent length adjuster is connected with the tangent length adjusting rod; the tangent length adjusting rod is connected with the blade fixed frame; and the blade can extend between the upper baffle plate and the lower baffle plate. The device can perform double-end-surface flat cutting for a lead delay element, so that the delay precision is improvement, and the precise delay detonation is realized.