A remote vehicle diagnostic and detection method based on instant messaging communication, comprising: responding to a communication connection instruction, obtaining an online terminal list and displaying the online terminal list; when detecting a target terminal selection instruction, obtaining a target terminal from the online terminal list, and establishing a communication connection with the target terminal; acquiring first instant messaging data and sending the first instant messaging data to the target terminal; receiving first order data sent by the target terminal according to the first instant messaging data; wherein the first order data comprises a vehicle basic information acquisition request, merchant information, payment information, and a remote simulation terminal connection address; when detecting a first order agreement instruction, establishing a connection with a remote simulation terminal through the remote simulation terminal connection address; obtaining electric control system information and basic information of the vehicle; when detecting a remote diagnostic instruction, sending the electric control system information and basic information of the vehicle to the remote simulation terminal; receiving and parsing remote adjustment instructions to obtain vehicle adjustment instructions; sending the adjustment instructions to the vehicle corresponding to the basic information of the vehicle; and when detecting a communication end instruction, disconnecting the connection with the remote simulation terminal S110), wherein the remote simulation terminal is adapted to simulate and restore the vehicle after loading the electric control system information and basic information of the vehicle. responding to a communication connection instruction, obtaining an online terminal list and displaying the online terminal list; when detecting a target terminal selection instruction, obtaining a target terminal from the online terminal list, and establishing a communication connection with the target terminal; acquiring first instant messaging data and sending the first instant messaging data to the target terminal; receiving first order data sent by the target terminal according to the first instant messaging data; wherein the first order data comprises a vehicle basic information acquisition request, merchant information, payment information, and a remote simulation terminal connection address; when detecting a first order agreement instruction, establishing a connection with a remote simulation terminal through the remote simulation terminal connection address; obtaining electric control system information and basic information of the vehicle; when detecting a remote diagnostic instruction, sending the electric control system information and basic information of the vehicle to the remote simulation terminal; receiving and parsing remote adjustment instructions to obtain vehicle adjustment instructions; sending the adjustment instructions to the vehicle corresponding to the basic information of the vehicle; and when detecting a communication end instruction, disconnecting the connection with the remote simulation terminal S110), wherein the remote simulation terminal is adapted to simulate and restore the vehicle after loading the electric control system information and basic information of the vehicle.