社会环境和经济环境的不稳定性推动了情事变更原则的确立。情势变更原则有丰富的理论基础,彰显了对社会实质公平的价值追求。但是由于立法不完善甚至是立法空白,致使情事变更原则在理论和实践中出现诸多问题与不足,本文试图结合合同落空理论,从实体和程序的角度提出相应措施加以完善。 The instability of the social environment and the economic environment has promoted the establishment of the principle of changing circumstances. The principle of changing circumstances has a rich theoretical foundation, highlighting the pursuit of the true value of society. However, due to imperfect legislation and even legislative gaps, many problems and deficiencies exist in theory and practice because of the imperfect legislation. This paper attempts to improve the corresponding measures from the perspective of entity and procedure by combining the theory of failure of contract.