Fujian Province, located in Southeast China, is a high-frequency impact zone for typhoons, where extreme precipitation events are jointly modulated by multi-scale weather systems. However,?the underlying physical mechanisms remain to be further explored. Using ground-based observations from Fujian Province and NCEP/NCAR (NCEP2) reanalysis data, this investigate the spatiotemporal distribution and the evolution of multi-scale moisture budget characteristics for 24 extreme typhoon-induced precipitation events during 2007–2022. Power spectrum analysis indicates that extreme precipitation is primarily modulated by synoptic-scale disturbances (SYN, 0–10 days) and quasi-biweekly oscillations (QBWO, 10–20 days). Moisture budget diagnostics further reveal that column-integrated moisture convergence is a key factor for the occurrence and persistence of precipitation. SYN exhibits a negative to the moisture budget 1–3 days prior to the events, shifts to a positive contribution 1–2 days after onset, but persists only briefly. In contrast, QBWO transitions from a negative to a positive phase 2–3 days before the events and sustains a positive contribution for 4–6 days afterwards. The intraseasonal low-frequency background consistently provides a positive contribution throughout the events. Vertical circulation analyses indicate that SYN and QBWO signals reinforce each other on the event day, generating pronounced moisture convergence and triggering extreme precipitation, with QBWO providing sustained moisture support. Results highlight the combined impacts of multi-timescale systems on extreme typhoon-induced extreme precipitation in Fujian and improve the understanding of its formation mechanisms.