The invention discloses a transverse cutting machine for manufacturing insulating bricks. According to the transverse cutting machine, pier blanks come out of a pier blank box, passes through a horizontal cutting machine, and then are subjected to transverse cutting, in which each pier blank with the length of 1.7 meters is cut into eight sections, and each section is on a floorboard cart. The transverse cutting machine is installed on a track, a square machine base (1) is arranged at both sides of the track, a lead screw base and a lead screw (2) are arranged in front of the machine base (1)and are driven by a motor (3) at the back of the machine base (1), the motor (3) and the lead screw (2) are arranged back to back, and a belt pulley of the motor (3) and a belt pulley of the lead screw (2) are driven by a triangle belt. The lead screw (2) in front of the machine base (1) drives a blade holder (4), an upper screw pipe and a lower screw pipe (5) are arranged at the upper portion ofthe blade holder (4), a blade elasticity ring (6), an elasticity screw (7), and a blade (8) are arranged at the lower portion of the blade holder (4), the blade (8) is circular and is formed by putting the two ends of a steel strap together, and two sections are obtained by cutting once through the transverse cutting machine.