矫直机是对金属棒材、管材、线材等进行矫直的设备。矫直机通过矫直辊对棒材等进行挤压使其改变直线度。一般有两排矫直辊，数量不等。也有两辊矫直机，依靠两辊（中间内凹，双曲线辊）的角度变化对不同直径的材料进行矫直。主要类型有压力矫直机、平衡滚矫直机、鞋滚矫直机等等。
这种的矫直过程是：辊子的位置与被矫直制品运动方向成某种角度，两个或三个大的是主动压力辊，由电动机带动作同方向旋转，另一边的若干个小辊是从动的压力辊，它们是靠着旋转着的圆棒或管材摩擦力使之旋转的。为了达到辊子对制品所要求的压缩，这些小辊可以同时或分别向前或向后调整位置，一般辊子的数目越多，矫直后制品精度越高。制品被辊子咬入之后，不断地作直线或旋转运动，因而使制品承受各方面的压缩、弯曲、压扁等变形，最后达到矫直的目的。Straightening machine is straightening of the metal bar, pipe, wire and other equipment. Straightening machine through the straightening roll extrusion of bar to the change of straightness. There are generally two row of straightening roll, any number. There are also two roll straightener, rely on two roll (middle concave, hyperbola roll) the Angle of the change on the materials of different diameter straightening. Main types of pressure straightening machine, balance roll straightening machine, shoe roll straightening machine and so on.
The straightening machine straightening process is: the position of the roll and be straightening products into some sort of movement direction Angle, two or three big initiative pressure roller, driven by motor to rotate the same, on the other side of the several small roller is driven pressure roller, they are against the rotating round rod or pipe friction spinning. In order to achieve the roll of products required by the compression, these small roller can adjust the position simultaneously or respectively forward or backward, generally, the more the number of roller straightening products after the higher precision. Products by the roll bite, constantly make linear or rotary motion, thus making products under various aspects of compression, bending, flattening deformation, finally achieve the goal of straightening.