The invention relates to a setting prevention device, in particular to a device for preventing concrete setting. The device for preventing concrete setting comprises a rear side plate, a supporting plate, a stirring support, a power mechanism, a differential mechanism, a stirring mechanism, a transmission mechanism, a delayed setting support, a rotating mechanism, a delayed setting box and a delayed setting cover. The differential mechanism comprises a differential shaft I, a baffle groove I, a differential bevel gear I, a differential belt wheel I, a differential shaft II, a differential bevel gear II, a differential bevel gear III, a differential shaft II and a differential belt wheel II, wherein the differential bevel gear I is fixedly connected to the rear end of the differentia shaftI and can prevent rapid setting of concrete in the long-distance transportation process. The concrete in the stirring support is stirred through the stirring mechanism, so that the setting speed of the concrete is decreased. The stirring resistance borne by the stirring mechanism is increased when the concrete slowly starts to set, the rotating speed of the stirring mechanism is decreased, and thedifferential mechanism supplies a set retarder into the stirring support through acceleration of the rotating mechanism, so that the setting speed of the concrete is further decreased.