Abstract Distributed SAR system adopts the flight model which receivers and transmitter are in different platform, that has many prominent merits, but the receiver and transmitter’s PRF can have error. The paper bases on the principle of bistatic SAR, establishes the influence model of the PRF error to imaging and interferometry, analyzes the influence of the PRF error to interferometric phase, and proposes the PRF precision request in this foundation. The simulation enunciates the validity of the model and the reasonableness of the PRF precision requirement.