The invention discloses a detecting system and a detecting method for a safety testing mode. The detecting system is used for preventing entering the safety testing mode after a chip testing circuit is abandoned. The detecting system for the safety testing mode comprises a time sequence logic control module, a detecting circuit module and a triggering module. The triggering module is used for generating a high-level or low-level triggering signal according to an on-off state. The time sequence logic control module outputs a high-level testing mode signal according to the low-level triggering signal, thereby making a chip enter the safety testing mode, or the time sequence logic control module outputs a low-level testing mode signal according to the high-level triggering signal, thereby making the detecting circuit module output a self-destroying signal for performing a self-destroying operation. Therefore the detecting system for the safety testing mode improves protecting effectiveness for chip sensitive information and accords with a majority of technological realizing requirements. The detecting system can be widely applied to various safety chips.