The invention discloses a small-diameter drill hole pressure relief method under the equivalent area. The small-diameter drill hole pressure relief method includes the following steps that first, a mine equivalent simulation model is established; second, the pressure relief parameter range of large-diameter drill holes is obtained; third, the pressure relief parameter of the large-diameter drill holes is optimized; fourth, the large-diameter drill holes are replaced with small-diameter drill holes equivalently, 401, the difference threshold is set, 402, the equivalent alternative arrangement of N small-diameter drill holes is established to replace the large-diameter drill holes with an optimal pressure relief parameter, 403, according to the order of increasing the number of the small-diameter drill holes, the pressure relief simulation is carried out and the equivalent alternative arrangement of drill holes is obtained; and fifth, the small-diameter drill holes are released. According to the small-diameter drill hole pressure relief method under the equivalent area, the parameter of the large-diameter drill holes is optimized according to mine actual conditions, the large-diameter drill holes are replaced with small-diameter drill holes equivalently so as to effectively avoid serious damage to the stability of a coal body caused by the oversized large-diameter drill hole diameter, the facts that the underground is equipped with special drilling equipment and the special drilling equipment cannot drill in the limited space of a tunnel are avoided, and the transportation difficulty of the equipment is reduced.