The invention provides a method and a device for establishing an earthquake acquisition and observation system, wherein the method comprises the steps of acquiring a pre-established first observation system which is orthogonally arranged on a to-be-observed work area; determining one or a plurality of azimuths with sparse shot-geophone distance distribution according to the surface element attribute of the first observation system; adding a shot-geophone point on each of the one or a plurality of azimuths, and furthermore performing shot arrangement on all shot points in the first observation system according to the rectangular arrangement dimension of the first observation system after the shot-geophone points are added, thereby obtaining a second observation system. The method and the device settle a problem of sparse shot-geophone distance distribution in an orthogonally configured observation system in prior art and realizes technical effects of relatively uniform azimuth and no abnormal sparse azimuth in the earthquake acquisition and observation system.