A car control system is disclosed. The car control system for controlling a car by being linked with a car control device (electronic control unit, ECU) that is installed inside the car for electronic control of the car can include: an authentication server configured to perform access authentication for a user terminal and configured to generate an authentication result based on least one of terminal information of the user terminal and vehicle identification information; and a car access device configured to be directly connected with the car control device through an internal network of the car and configured to determine whether a car control request for control of the car by the user terminal is to be relayed to the car control device according to the authentication result of the user terminal.