A vehicle security control method based on an open platform, wherein the open platform comprises a software development kit in which a first control protocol, which is a protocol encrypted by a security gateway, is encapsulated, the software development kit provides an application programming interface, API, function interface, and the security control method comprises the following steps performed in a vehicle: receiving a call request from a third-party device for a target API function interface of the open platform; converting the call request by using the software development kit to generate a first control signal that meets a requirement of the first control protocol and that is used for controlling a first vehicle component in the vehicle; and transmitting the control signal to the security gateway through a first bus, to enable the security gateway to perform protocol conversion on the first control signal to generate a second control signal that meets a requirement of a second control protocol, and transmitting the second control signal to an in-vehicle network to control the first vehicle component in the vehicle; wherein after the transmitting the first control signal to a security gateway through a first bus, the method further comprises: receiving, by further using the open platform, vehicle state information transmitted by the security gateway, where the vehicle state information is obtained and sent by the vehicle to the security gateway after the first vehicle component executes the second control signal; converting the vehicle state information to the parameter value corresponding to the target API function interface by using the software development kit; and transmitting the parameter value of the target API function to the third-party device through the target API function interface. receiving a call request from a third-party device for a target API function interface of the open platform; converting the call request by using the software development kit to generate a first control signal that meets a requirement of the first control protocol and that is used for controlling a first vehicle component in the vehicle; and transmitting the control signal to the security gateway through a first bus, to enable the security gateway to perform protocol conversion on the first control signal to generate a second control signal that meets a requirement of a second control protocol, and transmitting the second control signal to an in-vehicle network to control the first vehicle component in the vehicle; wherein after the transmitting the first control signal to a security gateway through a first bus, the method further comprises: receiving, by further using the open platform, vehicle state information transmitted by the security gateway, where the vehicle state information is obtained and sent by the vehicle to the security gateway after the first vehicle component executes the second control signal; converting the vehicle state information to the parameter value corresponding to the target API function interface by using the software development kit; and transmitting the parameter value of the target API function to the third-party device through the target API function interface. receiving, by further using the open platform, vehicle state information transmitted by the security gateway, where the vehicle state information is obtained and sent by the vehicle to the security gateway after the first vehicle component executes the second control signal; converting the vehicle state information to the parameter value corresponding to the target API function interface by using the software development kit; and transmitting the parameter value of the target API function to the third-party device through the target API function interface.