The invention relates to an identity authentication method and device based on a block chain, a computer readable storage medium and computer equipment. The method comprises the following steps: receiving a service request of a user, obtaining authorization information of the user according to the service request, searching a target block corresponding to the authorization information from a blockchain, and obtaining registration data of a user corresponding to the authorization information from the target block, calling an intelligent contract corresponding to the service request when the authorization verification is passed, executing the declared identity authentication logic by the intelligent contract, obtaining an identity authentication result based on the registration data, and feeding back the identity authentication result. For the service provider, the identity information of the user cannot be directly contacted, and the identity authentication result fed back by the blockchain can be obtained or used only on the premise of user authorization, so that for the user, the user can be prevented from directly providing the identity information of the user for a merchant, and the problem of leakage of personal information of the user is avoided from the source.