本申请涉及一种药皮焊环及其制备方法，药皮焊环包括钎料和钎剂，钎料呈环状，钎剂通过粘结剂粘结在钎料表面形成一层均匀的药皮。所述粘结剂为聚氨酯和稀释剂的混合物，稀释剂为乙酸丁酯、丙酮、碳酸二甲酯中的一种或多种，其中聚氨酯占粘结剂总质量的80-90%，稀释剂占粘结剂总质量的10-20%。所述药皮焊环的制备方法包括以下步骤：钎料表面形成均匀的粘结剂层；钎剂粘结在沾有粘结剂的钎料上构成药皮焊环半成品；对药皮焊环半成品进行加热抛光固定成型。本申请结构简洁，药皮粘结力强，经过三次元震动研磨机处理后外观均匀致密，厚度稳定性好，药皮焊环易于装配与使用。

The invention relates to a coating soldering ring and a preparation method thereof. The coating soldering ring comprises brazing filler metal and brazing flux, wherein the brazing filler metal is in aring shape, and the brazing flux is bound to the surface of the brazing filler metal through a binder to form a layer of uniform coating. The binder is a mixture of polyurethane and a diluting agent,the diluting agent is one or more of butyl acetate, acetone and dimethyl carbonate, the polyurethane accounts for 80-90% of the total mass of the binder, and the diluting agent accounts for 10-20% ofthe total mass of the binder. The preparation method of the coating soldering ring comprises the following steps that a uniform binder layer is formed on the surface of the brazing filler metal; thebrazing flux is bound to the brazing filler metal with the binder to form a semi-finished coating soldering ring; and the semi-finished coating soldering ring is heated, polished and fixed to be formed. The coating soldering ring is concise in structure and high in coating binding force, the appearance is uniform and compact after treatment by a three-dimensional vibration grinder, the thickness stability is good, and the coating soldering ring is easy to assemble and use.