The invention discloses an automatic concrete slump test device. The device comprises a machine, a slump barrel and a driving mechanism, wherein a bottom plate is arranged above the machine, the bottom plate is fixedly connected with support columns, the support columns are fixedly connected with a top plate, screw levers are arranged between the top plate and the bottom plate, the screw levers and screw nuts are in clearance fit, the screw nuts are fixedly connected with a clamp block, two sides of the slump barrel are fixedly connected with first slot pieces respectively, the first slot pieces are fixedly connected with second slot pieces through stem bolts, the first slot pieces and the second slot pieces are separately provided with slots that are opposite, and the clamp block is sheathed in the slots. In the automatic concrete slump test device, a timing belt drives the two screw levers to rotate synchronously, so that the two screw nuts are guaranteed to ascend or descend simultaneously, and the slump barrel is not affected by transverse force and torsion in the test, therefore, the test results are accurate and reliable, the slump barrel and the screw nuts can be fixed rapidly through the stem bolts, and measurement errors are reduced.