The invention provides a trailing arm lock with detachable and replaceable trailing arms for a double-column automobile elevator. The trailing arm lock with the detachable and replaceable trailing arms for the double-column automobile elevator comprises a cross beam, a rising and falling slide, two long trailing arms, two rotary shafts, two supporting assemblies, two short trailing arms, two trailing arm semi-teeth, two trailing arm lock teeth and two locking pins. The cross beam is provided with connecting through holes and installing through holes. The rising and falling slide is connected to the cross beam. Each long trailing arm comprises a straight rod, a straight plate, a first connecting plate and a second connecting plate. The two rotary shafts are arranged in the long trailing arms and the connecting through holes of the cross beam in an inserted manner. Each supporting assembly comprises a supporting rod and a supporting platform. Each short trailing arm comprises a connecting piece and lap-joint pieces. According to each trailing arm semi-tooth, the arc-shaped outer edge is a convex tooth face, the bottom face is provided with an arc-shaped groove, and the surface is provided with fixed holes. The trailing arm lock teeth comprise connecting pipes and meshing parts, the inner walls of the meshing parts are provided with concave tooth faces, the connecting pipes are communicated with the installing through holes of the cross beam, and the concave tooth faces of the meshing parts are meshed with the convex tooth faces. One ends of the locking pins are provided with pulling rings, and the other ends of the locking pins are inserted into the installing through holes of the cross beam through the connecting pipes and extend out of the cross beam through the lower surface of the cross beam. According to the trailing arm lock, the structure is simple, the trailing arms are detachable and replaceable, the meshing degree between the trailing arm lock teeth and the trailing arm semi-teeth is high, and limiting and locking on the trailing arms can be effectively achieved.