Disclosed is an Ethernet-based vehicle control system and method. The Ethernet-based vehicle control system (method) according to the present invention includes: a router for connecting a vehicle internal network and a vehicle external network; a vehicle electronic element connected to and communicating with the router; and a third-party module newly mounted on a vehicle to control the vehicle electronic element, and the third-party module may be controlled by a remote controller through the vehicle external network. Here, the third-party module may be a remote start control device. According to the present invention, since a third-party module can be freely installed and replaced based on Ethernet, various services related to a vehicle may be realized through a vehicle external network.