An application management method of a Point of Sale, POS, terminal, applied to a system comprising the POS terminal, an application server and an application development server in communication connection, wherein the method comprises: the POS terminal sending an application download request to the application server; the application server sending an application installation package corresponding to the application download request to the POS terminal; the POS terminal receiving an application installation package sent by the application server, and generating a first verification message according to content of the received application installation package; the POS terminal sending the first verification message to the application server; the application server comparing the first verification message with a second verification message; after determining that the first verification message is consistent with the second verification message, the application server sending a permit-to-install message to the POS terminal; the POS terminal installing an application according to the received application installation package after receiving a permit-to-install message sent by the application server; wherein the second verification message is generated and stored by the application server, in response to determining that the application installation package has passed an security check after receiving the application installation package from the application development server, according to content of the application installation package before sending the application installation package to the POS terminal; characterized in that the method further comprises a following method of periodically verifying installed applications on the POS terminal: the POS terminal generating a verification message list according to content of application installation packages installed in the POS terminal; the POS terminal sending the verification message list to the application server; the application server comparing verification messages in the verification message list with stored verification messages; the application server determining an abnormal application on the POS terminal according to the inconsistent verification message, after determining that a verification message in the verification message list is inconsistent with the stored verification messages; the application server sending a reminder message corresponding to the abnormal application to the POS terminal. the POS terminal sending an application download request to the application server; the application server sending an application installation package corresponding to the application download request to the POS terminal; the POS terminal receiving an application installation package sent by the application server, and generating a first verification message according to content of the received application installation package; the POS terminal sending the first verification message to the application server; the application server comparing the first verification message with a second verification message; after determining that the first verification message is consistent with the second verification message, the application server sending a permit-to-install message to the POS terminal; the POS terminal installing an application according to the received application installation package after receiving a permit-to-install message sent by the application server; wherein the second verification message is generated and stored by the application server, in response to determining that the application installation package has passed an security check after receiving the application installation package from the application development server, according to content of the application installation package before sending the application installation package to the POS terminal; characterized in that the method further comprises a following method of periodically verifying installed applications on the POS terminal: the POS terminal generating a verification message list according to content of application installation packages installed in the POS terminal; the POS terminal sending the verification message list to the application server; the application server comparing verification messages in the verification message list with stored verification messages; the application server determining an abnormal application on the POS terminal according to the inconsistent verification message, after determining that a verification message in the verification message list is inconsistent with the stored verification messages; the application server sending a reminder message corresponding to the abnormal application to the POS terminal. the POS terminal generating a verification message list according to content of application installation packages installed in the POS terminal; the POS terminal sending the verification message list to the application server; the application server comparing verification messages in the verification message list with stored verification messages; the application server determining an abnormal application on the POS terminal according to the inconsistent verification message, after determining that a verification message in the verification message list is inconsistent with the stored verification messages; the application server sending a reminder message corresponding to the abnormal application to the POS terminal.