The embodiment of the invention provides a method for reducing vehicle same-frequency interference and vehicle-mounted keyless starting equipment. The method comprises the steps that a controller generates a preset synchronization head as a synchronization head in a radio frequency communication protocol according to preset identification information; the controller uses a preset synchronization head to set a radio frequency receiving device; the controller sends a first radio frequency signal to the matching key, and writes the preset synchronization head into the matching key, so that the preset synchronization head is adopted to send key information when the matching key executes the matching process; the radio frequency receiving device judges whether the synchronization head receivingthe key information is consistent with a preset synchronization head or not; and if so, the radio frequency receiving device transmits the key information to the controller and executes the matchingprocess, otherwise, the radio frequency receiving device gives up the transmission of the key information to the controller. According to the technical scheme of the embodiment of the invention, the same-frequency interference occurring in the matching process of the automobile end and the key end of the PEPS system can be reduced, and the influence of the same-frequency interference on normal matching and normal offline of the automobile is reduced.