The invention provides a trusted starting method and a device of a computing platform. The method comprises the following steps: controlling a processor of an operating system to be started to be in areset state; Invoking a bootstrap program of an operating system to be started, and measuring the bootstrap program for the bootstrap program; Canceling the control that the processor is in the resetstate when the metric is passed, controlling the processor to load and start the bootstrap program; Calling the system kernel to be run of the operating system to be started, and carrying out systemkernel measurement on the system kernel to be run; Running the system kernel to be run when the metric is passed; Calling the system and application program of the operating system to be started, andmeasuring the system and application program; Controling trusted startup of the operating system to be started when the metric is passed. By implementing the invention, the reset state of the processor can be controlled, the safety of the bottom application program and the operating system of the computing platform can be ensured, the defense capability of the entire computing platform can be improved, and the safe start of the computing platform can be ensured.