Abstract: As the important content of the penalty alteration system, temporary execution outside prison is under supervision of the People's Procuratorate. However, the supervision by the People's Procuratorate is basically"external", "after-the-event" and lacking a compulsory force, which cannot guarantee the actual effect of supervision. Against the background of the implementation of Criminal Procedure Law of the People's Republic of China and Criminal Law Amendment (eight), this article comes up with a more comprehensive supervision mechanism to ensure that the work of temporary execution outside prison can be legally and smoothly carried out.