A dust collector provided with a shunt guide plate includes a main body, a filter drum, a dust collecting barrel and an induced draft device. A cover plate is fixed between the main body and the dust collecting barrel, having a central portion bored with an insert hole corresponding to the main body, and a guide plate is transversely disposed under the cover plate. Thus, the induced draft device is started to absorb airflow with dust into the main body and, when passing through the insert hole of the cover plate, the airflow will be stopped by the guide plate and forced to flow through two sides of the guide plate to form a shunt effect. Thus, when airflow gets into the dust collecting barrel, the dust in the dust collecting barrel will not be affected to rise, enhancing dust collecting effect of the dust collecting barrel.