A tolerant key verification method is provided. The tolerant key verification method comprises the following steps. A first key is generated instantly according to first characteristic values from a user terminal and is transmitted to a verification server to perform a comparison. When a data in the verification server matches the first key, the verification server makes no response and asks a network-service server to provide a network service to the user terminal. When the data doesn't match the first key, the verification server makes no response. When no data is available, the verification server makes no response and asks a message server to send a key-regeneration signal to the user terminal such that the user terminal generates a second key instantly according to second characteristic values. The verification server saves the second key and asks the network-service server to provide the network service to the user terminal.