The invention relates to a full-load static characteristic test device of a bolt joint surface unit, comprising a box body, wherein a transverse beam is arranged above the box body; the transverse beam is fixedly connected with the box body through a left upright post and a right upright post; a lower test piece is arranged on the table surface of the box body; an upper test piece is arranged on the lower test piece; a preloaded assembly is arranged between the upper part of the upper test piece and the transverse beam; the upper test piece is connected with the lower test piece through the preloaded assembly; cantilevers at the two ends of the upper test piece are respectively provided with a vertical load applying assembly; each load applying assembly is respectively connected with the transverse beam upwards; cantilever end heads at the two ends of the upper test piece are respectively provided with a connecting piece; and a horizontal load applying assembly is respectively arranged between each connecting piece and right upright post of the transverse beam as well as between each connecting piece and the left upright post of the transverse beam. The full-load static characteristic test method of the bolt joint surface unit of the invention can be used for carrying out a pre-tightening force test, a normal operating load static characteristic test, a tangential operating load static characteristic test, a bending moment operating load static characteristic test and a torque operating load static characteristic test of the bolt joint surface unit by utilizing the test device according to the different structural combinations.