Provided are an information transmission method, a network device and a terminal device. The method comprises: a first network device obtains indication information, the indication information being used for indicating integrity protection (IP) check failure of data on a data radio bearer (DRB); the first network device sends the indication information to a second network device. In embodiments of the present application, by means of the indication information, the second network device can update a secret key of the terminal device during the IP check failure of data on the DRB, or the second network device can release RRC connection of the DRB. In this way, the potential safety hazard is eliminated, the communication security is ensured, and therefore, the success rate of data transmission is improved.