The invention discloses a micro-seismic monitoring-based gob-side excavation roadway dynamic monitoring and stability evaluating method. The method comprises the following steps: 1, installing a high-precision micro-seismic monitor system in a gob-side excavation roadway; 2, acquiring the positions, energy and frequency of surrounding rock cracking micro-seismic events; 3, distributing a plurality of roadway cross section convergence monitoring stations, acquiring the cross section convergence numerical values of a solid coal side and a gob-side side of a roadway, and calculating the average convergence value of the cross sections of the solid coal side and the gob-side side of the roadway; 4, selecting an anchor rod or an anchor rope to perform a pull-out test on the gob-side side and the solid coal side respectively, and calculating the average drawing force of the anchor rod or the anchor rope; 5, calculating the increment rate of the energy of cumulative micro-seismic events, the increment rate of energy density of micro-seismic events in unit volume, the increment rate of the frequency of the cumulative micro-seismic events, the reduction rate of the average drawing force of the anchor rod or the anchor rope, and the increment rate of the average convergence amount of the cross sections; 6, based on various evaluation values obtained in the step 5, establishing a comprehensive quantitative evaluation index of the gob-side excavation roadway, and performing quantitative evaluation on the stability of the gob-side excavation roadway.