2018年认罪认罚从宽制度正式被确立为一项法律制度。在该项制度中被追诉人通过自愿认罪认罚来换取程序上的简化和实体上的从宽，自愿性是程序正当合法的基础与前提。本文以此为切入点，通过分析不同阶段保障自愿性需要满足的程序要求或必要条件等来反思目前存在的问题及成因，并据此提出完善建议，希望对保障自愿性发挥一定的作用。 文章的第一部分主要是绪论。简要梳理了该项制度的产生背景，以及认罪认罚自愿性的基本范畴。第二部分是侦查阶段认罪认罚自愿性保障问题。为保障自愿性需要详细的权利告知程序和专门的讯问程序，结合目前被追诉人在侦查阶段知悉权和值班律师权利缺失等现状，提出了明确权利告知的方式和内容；并且赋予值班律师在侦查阶段更多权利，对讯问过程实行录音录像制度等建议。第三部分是审查起诉阶段自愿性的保障问题。在此阶段为了保障认罪认罚自愿性需要有独立的量刑协商机制以及证据开示程序。目前我国量刑规范不完善和证据开示程序缺失，为了充分保障自愿性，需要建立规范的量刑协商机制和证据开示程序。第四部分研究的是审判阶段的自愿性保障问题。在这个阶段保障自愿性需要获得有效的法律帮助、独立有效的自愿性审查程序、反悔后的撤回程序、以及专门的上诉审查机制来支撑。当下我国认罪认罚从宽程序中法律援助律师的服务水平和质量不高，自愿性审查的方式和内容模糊，对撤回权和上诉权的认识存在偏差，所以需要通过建立专门的法律援助律师队伍，构建和完善认罪认罚自愿性审查程序、撤回程序和上诉审查机制等来实现对自愿性的保障。

The plea-guilty and lenient punishment system was formally established as a legal system in 2018. In this system the accused exchanges simplification in procedure and preferential treatment in substance by voluntarilymaking confession against himself. Voluntariness is the foundation and precondition of the procedure.Taking this as the starting point, this paper reviews the current problems and causes by analyzing the procedures and conditions that need to be met in different stages, and puts forward some suggestions for improvement, hoping to play a certain role in guaranteeing voluntariness. The first part is an introduction, mainly introduces the backgroundof the plea-guilty and lenient punishment system and the basic category of voluntariness of plea-guilty.The second part introduces the voluntary guarantee of confession and punishment in the investigation stage. In order to guarantee the voluntariness, it is necessary to set up detailed right informing procedure and special interrogation procedure, but considering that at present the defendant's right to know is imperfect and the lack of rights of duty lawyers in the investigation stage, this paper puts forward some specific suggestions on clearly informing contents and methods, giving duty lawyers more rights at the investigation stage, and implementing recording and video recording system during the whole interrogation process.The third part mainly introduces the voluntary guarantee of confession and punishment in the stage of review and prosecution. At the stage of examination and prosecution, in order to guarantee the voluntariness of pleading guilty and confessing punishment, we need to set up independent sentencing consultation mechanism and evidence discovery procedure. At present, the sentencing regulations of lenient procedure for confession of guilt and penalty are imperfect, and our country has not yet established evidence discovery system. In order to ensure voluntariness, we need to establish standardized sentencing consultation mechanism, and establish a lenient procedural evidence discovery system for confession and punishment. The fourth part mainly introduces the voluntary guarantee of confession and punishment in the trial stage. In the trial stage, to guarantee the accused's voluntariness of pleading guilty and confessing punishment, we need substantive legal assistance, independent and effective voluntary review procedures and specialized appeal procedure. At present, the service level and quality of legal aid lawyers in the lenient procedure are not high, the way and content of voluntary review are vague. And we have cognitive bias of the withdrawal right and the appeal right. Therefore, we need to establish a special legal aid lawyer team, construct and improve the voluntary review procedure of confession and punishment, withdrawal procedure and appeal review mechanism to achieve the guarantee of voluntariness.