The invention relates to the technical field of 
network security, and provides an identity 
authentication method and 
system based on 
sound wave communications. The method includes the steps that 1, feature codes are implanted into an 
authentication device; 2, binding information is obtained according to 
user information and the feature codes in the 
authentication device of a user, and the binding information is recorded in a 
server-side; 3, 
user equipment of the user has access to the 
server-side to obtain the feature codes in the binding information; 4, the 
user equipment encodes connecting request information containing the feature codes into 
sound wave signals and broadcasts the 
sound wave signals; 5, the authentication device monitors the sound wave signals, a sound wave link is established between the authentication device and the 
user equipment according to a monitoring result, and identity authentication is provided to the user equipment. According to the identity authentication method and 
system based on sound wave communications, common potential safety hazards of existing sound wave equipment are avoided, trusted identity authentication of each 
service system can be enhanced, the authority and the security of data of each 
service system are improved, 
power consumption of the authentication device is saved, and meanwhile user experience is improved.