双横臂悬架又称双A臂悬吊系统（英语：double-wishbone suspension）是一种使用两两平行上短下长的三角形控制臂（上下等长会造成轮胎上下摆动时过度左右移动，而引起严重损耗）的独立式悬吊设计。每枝A臂（A-arm）有两个可动关节连接于底盘上，还有一个连接在转向座（Knuckle，**俗称为「羊角」）上，并设备了避震器和弹簧来控制垂直方向的运动。双A臂设计让工程师得以仔细的控制轮胎在车辆运转时的运动状态，可控制的参数包括外倾角（Camber angle）、后倾角（Caster angle）、擦刮半径（Scrub radius）、束角（Toe angle）及滚动中心（Roll center）的高度等等。此外，A臂也常被用于其他的悬吊系统如麦弗逊悬吊（MacPherson strut）悬吊系统等等。

In automobiles, a double wishbone (or upper and lower A-arm) suspension is an independent suspension design using two (occasionally parallel) wishbone-shaped arms to locate the wheel. Each wishbone or arm has two mounting points to the chassis and one joint at the knuckle. The shock absorber and coil spring mount to the wishbones to control vertical movement. Double wishbone designs allow the engineer to carefully control the motion of the wheel throughout suspension travel, controlling such parameters as camber angle, caster angle, toe pattern, roll center height, scrub radius, scuff and more.