The invention discloses an efficient blasting excavation construction method for an ultra-deep foundation pit. The efficient blasting excavation construction method comprises the following steps of terrain investigation, side slope excavation, side slope protection, safety protection enclosure establishment, drilling operation, charging, plugging, stepped blasting and slag removal. The efficient blasting excavation construction method for the ultra-deep foundation pit is more scientific and reasonable; and by adopting the mature side slope protection technology, the rock stratum excavation construction technology, the safety enclosure establishment, strict drilling operation, charging technology, the standard operation of blasting and the detection means adopting strict measures, the riskcoefficient in the construction process can be effectively reduced, the blasting safety is greatly improved, meanwhile the influence of blasting on the surrounding environment can be effectively reduced, the blasting efficiency is high, the cost is low, and the efficient blasting excavation construction method is worthy of popularization.