Combined with the high quality Fabry-Perot (F-P) optical microcavities, we studied the thermal stability of G-quadruplex DNA structure laser-based high resolution melting (HRM) analysis. DNA solutions with three different concentrations of K⁺, which corresponds to different thermostablility of the G-quadraplux DNA structure in the solution, are studied. Experimental results show that DNA structure with different K⁺ concentrations can be well distinguished by laser-based HRM curves. Further, by analyzing the laser thresholds of different DNA solutions at arbitrary temperature, it is found that the melting temperature of the curves can be well decreased by using a lower pump energy.