The invention discloses a detection method and device for OBS detection point drift. The method includes the following steps of: acquiring the seabed depth at the location of each detection point of an OBS, and determining the theoretical zero-offset distance seismic data first arrival time of each detection point according to the seabed depth and sea water velocity; acquiring the seismic data first arrival time and the offset distance of each detection point; determining the actual zero-offset distance seismic data first arrival time of each detection point according to the seismic data firstarrival time and the offset distance of each detection point and the sea water velocity; calculating the residual error of each detection point according to the theoretical zero-offset distance seismic data first arrival time and the actual zero-offset distance seismic data first arrival time of each detection point; and comparing the residual error of each detection point with a preset thresholdto determine the detection point where the drift occurs. According to the method provided by the invention, the offset of each OBS detection point in the whole work area can be simultaneously checked, the phenomenon of wasting a lot of time due to a manual one-by-one check method can be avoided, the detection efficiency can be effectively improved, and the detection accuracy can be ensured.