In order to obtain a silicon-based light source with high quantum efficiency, a micron-sized round hole cavity array was fabricated on monocrystalline silicon wafer in air by using nanosecond pulsed laser. The properties of the sample after annealing at high temperature were investigated. Firstly, the quantum dots formed in the cavity had a stronger emission near 710 nm in photoluminescence (PL) measurement. Then, annealing at 1 000 ℃, the PL spectra before and after annealing were compared by controlling the annealing time. The variation trends of spontaneous and stimulated emission were observed. Annealing for 20 min, the PL intensity was various at different positions in the cavity, and it is found that the PL emission at the cavity edge is the strongest, which may be related to a large number of quantum dots distributed on the edge of the cavity. Finally, adopting standard LED calibration, the maximum PL external quantum efficiency (PL-EQE) in the cavity was measured. Experimental results indicate that the external quantum efficiency in the cavity after annealing can reach 9.29%.