通过对敦煌遗书中地论学派相关文献的梳理，结合隋代高僧净影慧远的著作，依"真如"与"真识"等核心概念剖析了地论学派佛性论的思想史脉络。这一思想的主要内容有以下几个方面：其一，以真如、法身等诠释佛性，以体用、隐显等探讨佛性的存在论与修道论；其二，以神虑、真心、真识心等诠释佛性，凸显佛性的主体意义，探讨佛性与佛身的因果意义，阐释佛性作为生死涅槃的同一体性，从而实现真理、本体与主体的统一。

This paper explores the intellectual sequence of Daśabhūmi-śāstra School's theory of Buddha-nature with Thusness(Tatathat), true unsullied consciousness and other key concepts by investigating the texts of Daśabhūmi-śāstra School in Dunhuang documents as well as the works of Huiyuan(523—592), an eminent monk in Jingying Temple in the Sui Dynasty(581—619). The main aspects of this theory are as follows: First, it interprets Buddha-nature through the concepts of Thusness and the embodiment of truth and law(dharmakāya) and discusses the doctrine of existence and cultivation methodology of Buddha-nature with the concepts of ti(substance) and yong(function), yin(concealing) and xian(revealing); second, it interprets Buddha-nature with the concepts of Buddha's spirit, true Buddha-mind, and true unsullied consciousness, highlighting the subject state of Buddha-nature. This paper also explores the causality between Buddha-nature and Buddha-embodiment(buddhakāya), showing the identical Buddha-nature in both reincarnation and nirvana. In this way, truth, substance and the subject are unified.