Synchronization is the key techniques for frequency hopping（FH）network construction.This paper puts forward an improved scheme of frequency hopping synchronization based on correlative researches.It mainly analyzes the principle by using a method combining synchronization-head with time of day（TOD）and studies the process of capturing synchronization and tracking.Time Division Multiple Access（TDMA）protocol uses the orthogonality of time to achieve channel sharing after synchronization’s achievement of a FH communication system.Slot synchronization and FH synchronization technique are used in this paper to realize TDMA-based Ad Hoc network construction.