Abstract: To verify the applicability of high-strength steel to lattice-steel towers, an experiment covering 21 Q420 specimens, involving 3 different sectional dimensions (2L160×12, 2L160×14, and 2L160×16) and 7 kinds of slenderness ratios ranging from 25 to 55, was run to test the bearing capacity of pinned-end cruciform section members. The test results were compared with the designed ones, showing that the existing design values of strength are 9.16% higher than the test results in average; the failure mode of the thin-walled open cross section member is a mixture of flexural buckling and local instability; and torsional buckling is not the main failure mode for this kind of member, which is different with the available design concepts.