ST企业停止特别处理（摘帽）后再次戴帽的风险是否会随退市制度改革而明显降低，对这一问题的理论考察对于评价退市制度改革的有效性至关重要。文章运用生存模型检验ST企业摘帽后的二次戴帽风险，以及这一风险随退市制度改革的动态变化，进而评估退市制度改革的有效性。研究发现：（1）尽管从年度演进上看ST企业摘帽后二次戴帽风险呈增大趋势，但随着退市制度改革的不断推进，二次戴帽风险呈降低趋势，摘帽企业摘帽后的绩效稳定性明显提升；（2）企业经历特别处理的时间越长，二次戴帽风险越低，且摘帽后有监管问询经历的企业二次戴帽风险更低；（3）随着退市制度改革对摘帽条件规定的日益严格化，ST处理时长与监管问询对企业二次戴帽风险的影响有所减弱；（4）ST企业摘帽后的财务违规受罚经历会增大二次戴帽风险，但随着退市制度改革的不断推进，这一风险逐渐降低，改革对于缓解处罚冲击下的绩效风险有积极作用。

Will the risk of adding the "*ST" mark to stocks of enterprises again after they removing it be significantly weakened with the continuous improvement of the delisting system reform? It is crucial to investigate this theory to evaluate the effectiveness of delisting system reform. With intention of evaluating the effectiveness of the delisting system reform, this paper tests the risk of adding the "*ST" mark to stocks of enterprises again after they removing it and the dynamic change of risk with the delisting reform by means of the survival model. The results show that: (1) Although from the perspective of annual evolution, the risk of adding the "*ST" mark to stocks of enterprises again after they removing it has shown a certain growth trend, with the continuous promotion of the delisting reform, such risk has significantly decreased, which means that the stability of performance of decapitated enterprises has significantly improved; (2) in terms of heterogeneity, the longer an enterprise has experienced the special treatment, the lower its risk of adding the "*ST" mark to its stock again, and enterprises with regulatory inquiry experience has lower likelihood of adding the "*ST" mark to their stocks again; (3) as the delisting reform has tightened the conditions for removing special treatment, the influence of special treatment processing time and regulatory inquiry on the risk of adding the "*ST" mark to stocks of enterprises again has weakened, and the reform has a certain substitute significance for risk improvement; (4) it is further proved from the perspective of financial violation that the financial violation punishment experience of enterprises after removing the "*ST" mark will increase the risk of adding the "*ST" mark to their stocks again but with the promotion of delisting reform, such risk is gradually reducing, which means that the reform plays a positive role in mitigating the performance risk under the impact of punishment.