Abstract: The causality cut-off standard for withdrawal from the joint principal offender focuses on the physical causality process， but the physical causality that has been caused is often difficult to change in fact， and its normative amendment is in conflict with the theory of the suspension of the individual principal offender. Although the psychological causality of the joint principal offenders not only realizes the attribution of the result， but also lays the foundation for principal criminal responsibility， it cannot be a sufficient basis for determining the intention of the crime. For the withdrawal from the joint principal offender， as long as active preventive behaviors can cut off the psychological causality between the withdrawer and the accomplished result， it will， regardless of the physical impact of the previous behavior， bear the responsibility of accomplice at most. If due to changes in active preventive efforts or objective situations， the withdrawer will not be responsible for the consequence resulting from his failure to foresee that the remaining accomplices continue to commit the crime， even if the causal influence remains.

Key words: withdrawal from the complicity; the joint principal offender; causality cut-off; psychological causality