Because you don't understand legal procedures. Bail pending trial is only a compulsory measure, not a sentence. Criminal detention and arrest, as well as bail pending trial, are all compulsory measures, but now they are only changed into compulsory measures, not sentencing, and nothing will happen if they are released on bail pending trial. The release certificate does not mean that the case is over and the representative is no longer in custody. However, the case is not over, and it has to enter the judicial process. After bail pending trial, you should be on call, otherwise your deposit will be deducted and you will be in danger of being thrown back into prison.
After bail pending trial, the case will be heard in court, but it is possible to sentence it to probation (execution outside prison). If no new crime is committed within the probation period, the original sentence will not be executed.
I hope my answer is helpful to you. If you are not clear, you can go to China Criminal Defense Network for enquiry. You can also find me through the link below.
Your friend, lawyer Zhao Li from China Criminal Defense Network.