The utility model discloses an experimental displacement testing device of pile bearing capacity relates to pile bearing capacity detection technical field, including sealed first container, sealed second container and differential pressure sensor, the second container is equipped with the fill orifice that can seal, and the second container is linked together with first container bottom, differential pressure sensor one end links to each other with the top of first container, and the other end links to each other with the top of second container. The utility model discloses an experimental displacement testing device of pile bearing capacity need not the benchmark roof beam, lays the construction simply, can eliminate the human factor influence, reduces to test the error, improves the measuring accuracy.