Forced confession is a big threat to the formation of evidence, which forces suspects to confess. But in modern legal society, we attach importance to voluntary confession. We should distinguish between torture and forced confession. Forced confession is an inevitable legal act and can't be measured by ideal standard. Instead, it should be limited by ‘non-arbitrariness confession excluded' rule. These rules are the products after reconciling legal conflict which contribute to the identification of voluntary confession. The psychological distress which investigating and interrogating brings is not equal to torture. To guarantee the legality of forced confession, we should hold the degree of voluntary. When using techniques of psychological forced confession of investigation and interrogation, we should study the activation of criminal mental trace and hypnotic suggestion, etc. The mental arousal of suspect will form forced confession situation. To achieve rationality of forced confession, we should identify the mental torture and mental forced confession. To eliminate mental torture, besides the rule of law, we should combine wisdom and strategy together. In all, we should seize the opportunity, force them to confess and finally win by a neck.