To provide a channel installation-type screen dregs crushing machine capable of reducing manufacturing costs.

This channel installation-type dregs crushing machine 1 comprises: a cylindrical tube body 3 which is vertically installed in a channel S, and which has an opening allowing the passage of water and screen dregs ; a spiral screw blade 4 which is coaxially provided inside the tube body 3; and a casing 6 which is provided outside the tube body 3, and which has an opening allowing the passage of the water and the screen dregs. A drive shaft 13 formed on the upper portion of the tube body 3 is connected to a motor 14 with a speed reducer. Only the tube body 3 is rotated so that the screen dregs can be crushed between the inner periphery of the tube body 3 and the screw blade 4 and between the outer periphery of the tube body 3 and the inner periphery of the casing 6.