Combined counter-force device for compression test of super-large bearing capacity foundation pile and construction method of combined counter-force device

The invention relates to an ultra-large bearing capacity foundation pile compression test combined counter-force device and a construction method thereof, and belongs to the field of foundations. The ultra-large bearing capacity foundation pile compression test combined counter-force device comprises an experimental device arranged at the top end of a test pile and a fixing structure for providing counter-force for the experimental device; the fixing structure comprises an anchor pile, a buttress, a force transmission main beam, a secondary beam, an anchoring and pressing main beam, a balancing weight and a pile beam connecting device for connecting the anchor pile and the anchoring and pressing main beam together. The anchor piles are arranged at the four corners with the test pile as the center, the buttresses are supported at the two ends of the force transmission main beam and supported at the two ends of the secondary beam, the force transmission main beam is arranged on the test device and located in th