To investigate the influence of dry etching on strained multiple quantum wells (SMQWs), we etch the cap layer of metalorganic chemical vapor phase deposition (MOCVD) grown InGaN/AlGaN SMQWs about 95 nm by inductively coupled plasma (ICP). Photoluminescence (PL) measurements show that, the photoluminescence intensity of the quantum wells is enhanced about 3 times after dry etching. The surface of the quantum well becomes fluctuant, the degree of roughness becomes larger, and it allows the photons generated within the quantum wells to escape surface more easily by multiple scattering at the rough surface. The theoretic calculation result shows that the pattern change of the quantum well surface causes the enhancement of the photoluminescence intensity about 1.3 times. On the other side, because the inductively coupled plasma power is small, the damage depth almost cannot reach the well layer, but the tunneling of Ar+ inside the quantum well structure may bring new luminescence centers, and enhances the photoluminescence intensity.