The invention relates to a safety anti-blocking construction process of soft aggregate in a mine underground ultra-deep hole. The safety anti-blocking construction process includes: drilling, judgingwhether the drilled hole and a water guide structure satisfy soft aggregate filling conditions, mounting a soft aggregate safety anti-blocking device into the drilled hole, filling the soft aggregateinto the water guide structure, starting a drilling rig at the same time to allow a drilling rig chuck to drive a central pipe to rotate rightwards, filling water into the central pipe at the same time through a water filling device connected to the head of the central pipe, ensuring that the high-temperature water flow in the drilled hole and the central pipe is constant before the water guide structure is filled with the soft aggregate until the soft aggregate is completely discharged from the drilled hole to the water guide structure, stopping the water filling and the soft aggregate filling, and taking out the soft aggregate safety anti-blocking device. By the safety anti-blocking construction process, the problem that the aggregate accumulates in the drilled hole and blocks the drilled hole during traditional soft aggregate filling which fills the soft aggregate into the mine underground hole.