Disclosed herein are an apparatus and method for processing vehicle data security based on a cloud. The method may include requesting, by a vehicle, a cloud center device to register a cloud-based vehicle data security service; generating, by the cloud center device, cloud-based vehicle data security policies and a pseudonym for the vehicle; requesting, by the cloud center device, an authentication center to generate a pseudonym certificate for the pseudonym and receiving the pseudonym certificate; transmitting, by the cloud center device, the cloud-based vehicle data security policies, the pseudonym, and the pseudonym certificate to the vehicle; generating, by the vehicle, vehicle state information, including accident record information and driving entity information, based on the cloud-based vehicle data security policies and transmitting the same to the cloud center device; and storing, by the cloud center device, the accident record information and the driving entity information in a database for each vehicle.