The invention discloses a separation method of exhaust noise in a vehicle and a sound source generating device. The separation method comprises the following steps that through low-frequency sound source and medium and high-frequency sound source, sound conduction functions from a measurement point near the exhaust to the measurement point in the vehicle are tested, and the low-frequency and medium and high-frequency conduction functions are combined to obtain an overall noise conduction function, and then the noise of the measurement point of an exhaust pipe orifice under operating conditionsmultiplies by the overall conduction function, and the result is the exhaust noise component in the vehicle. Compared with the prior art, the separation method of exhaust noise in the vehicle can accurately separate the exhaust noise component from total noise in the vehicle; obtain a time-domain signal of the exhaust noise component to evaluate the exhaust noise quality, so that a reference is provided for the optimization of the exhaust noise; and overcomes the defect that the existing technology can not accurately separate the exhaust noise component in the vehicle for quantitative analysis.