A system for customizing application services of a data card comprising the data card and an over-the-air server, wherein the data card is configured to send an application service customization request to the over-the-air server, and customize a corresponding application service according to a configuration command returned by the over-the-air server; and the over-the-air server is configured to return the predefined configuration command to the data card if it is determined that an operation of the data card is valid according to the application service customization request sent by the data card; characterized in that, wherein, the data card is further configured to customize or update the corresponding application service according to the received configuration command, and return an acknowledgment message to the over-the-air server; wherein the system further comprises a customization proxy database connected to the over-the-air server, the data card comprising an over-the-air proxy module and a service database which are connected to each other, wherein the over-the-air proxy module is configured to query information of all supported application services from the service database, construct a data packet containing configuration information of the application service, which is requested to be customized, to send to the over-the-air server, customize the application service according to the configuration command returned by the over-the-air server, and return the acknowledgment message; the service database is configured to store and manage a configuration file controlling service customization and information of all application services supported by the data card, including service types of the application services and their corresponding service customization request codes; the customization proxy database is configured to store and manage configuration information and its corresponding configuration command of all application services supported by the data card, the configuration information including an application service customization request code, a model number and version number of the data card, and an international mobile equipment identity of the data card; and the over-the-air server is configured to receive the data packet, then compare the configuration information of the application service contained in the data packet with the configuration information of the corresponding application service queried from the customization proxy database, determine that the operation of the data card to request customization of the application service is valid if the configuration information of the application service contained in the data packet is consistent with the configuration information of the corresponding application service queried from the customization proxy database and it is determined that the data card has not requested customization of the same application service according to configuration records of the customization of the application service of the data card, and return the configuration command to the data card while recording the configuration of the application service of the data card. the over-the-air proxy module is configured to query information of all supported application services from the service database, construct a data packet containing configuration information of the application service, which is requested to be customized, to send to the over-the-air server, customize the application service according to the configuration command returned by the over-the-air server, and return the acknowledgment message; the service database is configured to store and manage a configuration file controlling service customization and information of all application services supported by the data card, including service types of the application services and their corresponding service customization request codes; the customization proxy database is configured to store and manage configuration information and its corresponding configuration command of all application services supported by the data card, the configuration information including an application service customization request code, a model number and version number of the data card, and an international mobile equipment identity of the data card; and the over-the-air server is configured to receive the data packet, then compare the configuration information of the application service contained in the data packet with the configuration information of the corresponding application service queried from the customization proxy database, determine that the operation of the data card to request customization of the application service is valid if the configuration information of the application service contained in the data packet is consistent with the configuration information of the corresponding application service queried from the customization proxy database and it is determined that the data card has not requested customization of the same application service according to configuration records of the customization of the application service of the data card, and return the configuration command to the data card while recording the configuration of the application service of the data card.