连杆机构是传递机械能的一种设备，通常是由刚体构件用转动副、移动副、球面副、球销副、圆柱副或螺旋副中的一种或几种联结而成的机械机构，因为上述联接副均属于低副，连杆机构也称为低副机构。

通过不同的设计与计算，连杆机构可实现转动、直线移动、往复运动和平面或空间的复杂函数运动轨迹。连杆机构设计包括轨迹实现、承载能力、结构设计等问题。最基本的连杆机构是平面四杆机构。

A mechanical linkage is an assembly of bodies connected to manage forces and movement. The movement of a body, or link, is studied using geometry so the link is considered to be rigid. The connections between links are modeled as providing ideal movement, pure rotation or sliding for example, and are called joints. A linkage modeled as a network of rigid links and ideal joints is called a kinematic chain.