To research a fast and nondestructive testing method of compaction quality of gravel soil subgrade, to evaluate the uniformity of compaction and to improve the gravel soils roadbed compacted quality, differential settlement and deformation modulus were measured by adopting level measurement and PFWD on designated points of gravel soils roadbed. The relationship of differential settlement between deformation modulus Evd is established. The compaction test standards of Evd base on different request of differential settlement are put forward. The compaction quality was evaluated by compaction tracking detection, the roadbed top 3D model of deformation modulus was established by the high density detection of gravel soil subgrade deformation modulus and the roadbed compaction uniform index defined. The compaction uniformity and the weak area of compaction were evaluated. The results of the study show that, according to the relationship between the differential settlement and Evd, the PFWD nondestructive testing can quickly and effectively evaluate gravel soil subgrade compaction condition, the homogeneous degree index can be used to evaluate the roadbed compaction evenness, the gravel soil subgrade compaction uniformity can be improved by adding compaction to the weak area.