A safety circuit for power takeoff (PTO) for use in an automobile and a method for controlling the same is disclosed. The safety circuit determines whether a PTO unit, driving a pump, and a transmission must be coupled to each other according to the speed of the automobile and operating states of a clutch switch and PTO switch manipulated by a driver without use of an additional power cutoff relay. Such a safety circuit provides a cost-effective system capable of reducing the number of system components and quickly performing a stable operation using a small number of components in comparison with a system equipped with a conventional safety device for PTO.