Accurately simulating the roplet mass distribution of supercooled large droplet （SLD） cloud is the latest requirement of airworthiness， and also the technical difficulty in current icing wind tunnel tests. Aiming at the drop cumulative mass distribution curve of freezing drizzle specified in 14CFR part 25， appendix O， the simulation study of SLD icing conditions is carried out in the icing wind tunnel. Based on the requirements of water droplet mass distribution， the matching analysis of the large-drop cloud and the small-drop cloud is carried out， and the large water droplet nozzle spray performance is measured under the existing spray conditions of the FL-61 wind tunnel. A freezing drizzle condition with drop mass distribution curves close to the conditions specified in Appendix O is successfully achieved at the center of the test section through the combination of two different liquid water content （LWC） and medium volume diameter （MVD） characteristics that generated separately with the small droplet nozzle and the large droplet nozzle.The results show that the method of separately simulating the large and small water droplet clouds with the corresponding water droplet mass distribution， and then combining spray can better predict and guide the construction of large water droplet clouds in the icing wind tunnel. At the same time， it verifies the feasibility of using two types of nozzles to simulate the cloud conditions with bimodal water droplet mass distribution in the icing wind tunnel.