The invention discloses an integral polygonal crushing separation device. The device comprises a crushing unit arranged behind a sediment separation unit; the cross section of the crushing unit is regularly polygonal; multiple pendulum bobs capable of rotating along with rotation of the crushing unit and used for crushing gravels are arranged on the inner wall of the crushing unit; dozens of teeth are arranged on the outer surfaces of the pendulum bobs; a vibration unit is arranged on the outer wall of the crushing unit, and includes a spring bracket for supporting the crushing unit and an eccentric vibration wheel; and the spring bracket realizes lifting through an extension unit. The integral polygonal crushing separation device has the advantages of capability of further crushing the gravels, better crushing effect and higher working efficiency.