本文介绍了适用于我国西北沙区的一种新型植树机的结构特点。4ZAG-30型沙生灌木栽植机以东方红-75拖拉机为动力,采用三点悬挂、复式开沟机构和半自动投苗机构。该机的锐角靴式开沟器刃部曲线是按照土壤的摩擦理论建立的新的设计理论,经过简化设计出来的,在实践中取得较好的效果。本文着重论述了复式开沟机构的设计依据与设计方法。 This paper introduces the structural characteristics of a new tree-planting machine suitable for sandy areas in the northwest of China. 4ZAG-30 sand shrubs planter with Dongfanghong -75 tractors as a driving force, the use of three-point suspension, double trenching institutions and semi-automatic investment seedling institutions. The acute angle of the machine blade opener blade curve is based on soil friction theory to establish a new design theory, after simplified design, and achieved good results in practice. This article focuses on the design basis and design method of double trenching mechanism.