The disclosure provides a key generation method and apparatus. The key generation method comprises: encrypting a first key factor generated by a first device with an initial key, and sending the encrypted first key factor to a second device through a first secure channel, wherein the initial key is a key preset for the first device and the second device; receiving, through the first secure channel, a second key factor encrypted with the initial key, wherein the second key factor is generated by the second device; decrypting the second key factor encrypted with the initial key and received through the first secure channel, so as to obtain the second key factor; and generating a shared key between the first device and the second device according to the first key factor and the second key factor. According to the disclosed embodiments, a gateway device is unable to acquire a shared key negotiated between a first device and a second device, ensuring the security of data transmitted there between, and further reducing the risk of data being illegally captured during transmission.