The invention discloses an anonymous user authentication method for a crowd sensing Internet of Things based on chaotic mapping, and relates to an anonymous user authentication method for the crowd sensing Internet of Things. The invention aims to solve the problems that the existing user authentication method is difficult to realize the resistance of various typical attacks and the calculation cost or the communication cost is relatively high. The method comprises the following steps: 1, a user is registered; 2, after the user is registered, the user logs in; When the user logs in, if the network is found to have an attack of stealing the smart card, the step 5 is executed; When the user logs in, if the network is not found to have the attack of stealing the smart card, executing the step3; 3, after the user logs in, the user and the server carry out bidirectional authentication, a secret key between the user and the server is established, and after the secret key is established, ifthe user needs to change the password, the step 4 is executed; If the user does not need to change the password, ending; 4, the user changes the password; And 5, the stolen smart card is removed. Themethod is applied to the field of crowd sensing internet of things anonymous user authentication.