The invention discloses a vehicle speed detection method. A whole vehicle runs at a preset speed v, so that vehicle speed detection can be executed on a vehicle speed test bed on a whole vehicle detection line; at the moment, the signal frequency detected by a meter is P, and the formula that k=v/P can be obtained after calculation; the value k is stored into a meter system and serves as a constant k during normal working of the meter; when the meter works normally, the vehicle speed v is equal to kP. According to the technical scheme, the vehicle speed detection method has the beneficial effects of convenience and feasibility; a meter software designer does not need to pay attention to the mechanical structure and relevant parameters of the whole vehicle, so that the technical clarification work of a supplier and a customer in a product development process is reduced, the development period is shortened, and the vehicle speed detection method is suitable for all vehicle types of which the appearances and the sizes of the meters are the same.