through model tests of pile groups under vertical load, the load-bearing behavior and pile group effects have been analyzed. It was indicated that the pile spacing increased to 6d, the bearing capacity tend to equal to that of six single piles, but the settlement was larger than that of single pile; the point resistance of super-long pile group was negligible, and the effective length was existent; the lateral friction of the pile group increased with the increase of pile spacing, when the pile spacing increased to 6d, the lateral friction of the pile group was still less than that of single pile, the coefficient of pile group effects tend to one; when the pile spacing was 7d, pile group effects was 1 by curve fitting. Results above can give references for design and construction of super-long pile group.