The utility model relates to a full-coherent radar receiver with expandable passage, which combines a monopole crossing ring receiving antenna and a high-frequency radar digital concerted receiver into a receiver unit and adopts USB bus and USB collector to connect multiple receiver units in series, wherein a receiver unit is the master control receiver unit and the other receiver units are the expanded receiver units; the master control receiver unit conducts sequential control to the expanded receiver units and the work time clocks of all receiver units are provided by the clock source of the master control receiver unit; the master control receiver unit provides the expanded receiver unit with the radar emission signal and local oscillator signal; the local oscillator signal of each expanded receiver unit is unified and provided by the frequency source of the master control receiver unit; the receiver can be expanded to six-way, nine-way or more; meanwhile, each radar receiver unit can not only compose the multi-way radar receiving system, but also work independently; the quantity of the radar passages can be configured flexibly, simple and easy to realize.