A method for data confidentiality protection based on an embedded universal integrated circuit card, eUICC, comprising: receiving, by an eUICC in a terminal device, an instruction message, wherein the instruction message is used for instructing, when the terminal device is not held by an authorized user, the eUICC to perform confidentiality protection processing on data in the eUICC; and performing, by the eUICC, confidentiality protection processing on the data in the eUICC according to the instruction message, wherein the instruction message is a subscription stop command; and the receiving, by an eUICC in a terminal device, an instruction message comprises: receiving, by the eUICC, the subscription stop command sent by the terminal device, wherein the subscription stop command is generated by the terminal device and sent by the terminal device to the eUICC after the terminal device receives a first paging message sent by a mobile network operator, MNO, device, the first paging message is sent by the MNO device to the terminal device after the MNO device determines, according to geographical location information reported by the terminal device, that the terminal device is stolen, the first paging message comprises identity information of the terminal device and a theft indication that is used for identifying that the terminal device is stolen, and the subscription stop command comprises the identity information of the terminal device and the theft indication; and sending, by the eUICC, a subscription stop response to, subscription management unit-securely routing, SM-SR by using the terminal device, wherein the subscription stop response comprises the identity information of the terminal device, identity information of the eUICC, and the theft indication. receiving, by an eUICC in a terminal device, an instruction message, wherein the instruction message is used for instructing, when the terminal device is not held by an authorized user, the eUICC to perform confidentiality protection processing on data in the eUICC; and performing, by the eUICC, confidentiality protection processing on the data in the eUICC according to the instruction message, wherein the instruction message is a subscription stop command; and the receiving, by an eUICC in a terminal device, an instruction message comprises: receiving, by the eUICC, the subscription stop command sent by the terminal device, wherein the subscription stop command is generated by the terminal device and sent by the terminal device to the eUICC after the terminal device receives a first paging message sent by a mobile network operator, MNO, device, the first paging message is sent by the MNO device to the terminal device after the MNO device determines, according to geographical location information reported by the terminal device, that the terminal device is stolen, the first paging message comprises identity information of the terminal device and a theft indication that is used for identifying that the terminal device is stolen, and the subscription stop command comprises the identity information of the terminal device and the theft indication; and sending, by the eUICC, a subscription stop response to, subscription management unit-securely routing, SM-SR by using the terminal device, wherein the subscription stop response comprises the identity information of the terminal device, identity information of the eUICC, and the theft indication. receiving, by the eUICC, the subscription stop command sent by the terminal device, wherein the subscription stop command is generated by the terminal device and sent by the terminal device to the eUICC after the terminal device receives a first paging message sent by a mobile network operator, MNO, device, the first paging message is sent by the MNO device to the terminal device after the MNO device determines, according to geographical location information reported by the terminal device, that the terminal device is stolen, the first paging message comprises identity information of the terminal device and a theft indication that is used for identifying that the terminal device is stolen, and the subscription stop command comprises the identity information of the terminal device and the theft indication; and sending, by the eUICC, a subscription stop response to, subscription management unit-securely routing, SM-SR by using the terminal device, wherein the subscription stop response comprises the identity information of the terminal device, identity information of the eUICC, and the theft indication.