The agricultural production in most areas of our country is still done by producers manually, and manual labor is not only inefficient, but also heavy and large workload. Based on this, a kind of agricultural lower limb exoskeleton mechanism is proposed and designed. The mechanism aims to help people achieve agricultural production better and faster. The 8 degrees of freedom (8-DOF) (Single leg) structure design of mechanical lower extremity exoskeleton was done. The three-dimensional (3D) model of the mechanism was established by using UG software. Simulation analysis of its motion was carried out based on the ADMAS software. According to the simulation results, the rationality of the design of exoskeleton mechanism is verified.