A secure service request processing method, executed by a trusted application that is deployed in a trusted execution environment, TEE, of an end-user device, wherein the trusted application externally provides several interfaces, each interface corresponds to one functional unit of the trusted application, the end-user device further comprises a rich execution environment, REE, a client application is deployed in the REE, and the method comprises: receiving, from the client application, a first service request for requesting the trusted application to execute a first service, wherein the first service request comprises a first expression and an input parameter of the first expression, and the first expression specifies a plurality of target interfaces related to the first service and an invoking sequence of the plurality of target interfaces, wherein each of the several interfaces corresponds to a serial number; executing, based on the input parameter, the plurality of target interfaces in turn in the invoking sequence to obtain a target execution result, the executing comprising: recording a serial number of any first interface among the plurality of target interfaces when or after executing the any first interface among the plurality of target interfaces in turn in the invoking sequence; and forming, based on a recorded serial number of each interface, a serial number sequence after completing execution of the plurality of target interfaces; and using the target execution result as a processing result of the first service request, and returning the processing result of the first service request and the serial number sequence to the client application for verification, by the client application, the correctness of the processing result based on the serial number sequence, the returning comprising: signing the serial number sequence by using a pre-generated private key to obtain a signed serial number sequence; and returning the processing result of the first service request and the signed serial number sequence to the client application. receiving, from the client application, a first service request for requesting the trusted application to execute a first service, wherein the first service request comprises a first expression and an input parameter of the first expression, and the first expression specifies a plurality of target interfaces related to the first service and an invoking sequence of the plurality of target interfaces, wherein each of the several interfaces corresponds to a serial number; executing, based on the input parameter, the plurality of target interfaces in turn in the invoking sequence to obtain a target execution result, the executing comprising: recording a serial number of any first interface among the plurality of target interfaces when or after executing the any first interface among the plurality of target interfaces in turn in the invoking sequence; and forming, based on a recorded serial number of each interface, a serial number sequence after completing execution of the plurality of target interfaces; and recording a serial number of any first interface among the plurality of target interfaces when or after executing the any first interface among the plurality of target interfaces in turn in the invoking sequence; and forming, based on a recorded serial number of each interface, a serial number sequence after completing execution of the plurality of target interfaces; and using the target execution result as a processing result of the first service request, and returning the processing result of the first service request and the serial number sequence to the client application for verification, by the client application, the correctness of the processing result based on the serial number sequence, the returning comprising: signing the serial number sequence by using a pre-generated private key to obtain a signed serial number sequence; and returning the processing result of the first service request and the signed serial number sequence to the client application. signing the serial number sequence by using a pre-generated private key to obtain a signed serial number sequence; and returning the processing result of the first service request and the signed serial number sequence to the client application.