The accuracy of pulse signal cycle detection of enhanced Loran receiver will directly affect its navigation, positioning and timing accuracy. Aiming at the shortcomings of cycle detection method, based on the linear digital average to improve the signal-to-noise ratio, the peak-to-peak ratio detection method and the polarity determination method are used to realize the joint detection of the pulse signal. The validity and anti-noise performance of the method are verified by simulation, which lays the foundation for high-precision navigation positioning and timing of modern digital enhanced Loran receiver