The invention discloses a coal pillar reinforcement system for gob-side entry driving and a use method thereof and belongs to the technical field of coal mine gob-side entry driving supports. The system comprises coal pillar reinforcement anchor cables, grouting drill holes, a grouting monitoring device and a grouting machine, wherein the coal pillar reinforcement anchor cables include anchoring segments, free segments and block gangue devices; each anchoring segment includes an airbag, a front fixing ring, a rear fixing ring and a grouting hole, wherein the front fixing ring and the rear fixing ring are used for fixing the airbag, the front fixing ring is located at the front end of the airbag, the rear fixing ring is located at the rear end of the airbag, and the grouting hole is formedin the rear fixing ring; each free segment includes a steel strand, a tray, a lock and an inner grouting pipe, one end of each inner grouting pipe is connected with the corresponding grouting hole, the other end of each inner grouting pipe is connected with the grouting monitoring device, each airbag is arranged in the length direction of the corresponding steel strand, and the outer circumferenceface of each steel strand is coated with the corresponding airbag. According to the system, coal pillar reinforcement in gob-side entry driving in one direction can be carried out, and the stabilityand bearing capacity of coal pillars are improved.