By home-made experimental setup with aqueous jets and dual-pulse laser-induced breakdown spectroscopy (LIBS) technique, the dual-pulse and single pulse LIBS are applied to the detection of Al trace element in AlCl3 aqueous and mixed compound solution jets. The optimum parameters of dual-pulse and single pulse LIBS experiment are presented. Both the dual-pulse and single pulse LIBS detection limits of mass fraction of Al element in AlCl3 aqueous and mixed compound solutions are obtained as 26.79×10-6, 28.85×10-6 and 11.93×10-6, 14.46×10-6 respectively under the optimum experiment conditions. It is shown that detection sensitivity of dual-pulse LIBS is enhanced dramatically compared to the single pulse case.