Because of the low spatial resolution of the conventional ground meteorological observation network in Sichuan and the lack of data representativeness, the vertical cloud structure and the microphysical conditions in clouds cannot be obtained completely. In view of this, a series of scientific observation experiments for largerange cloud systems have been conducted in Sichuan since 2014. Observed objects are mainly stratiform clouds and stratified mixed clouds with embedded convection in Sichuan Basin and cumuliform clouds (convective clouds). This paper addresses six aspects of the scientific experiments, such as the objectives, regions, observation elements, observation layout design, observation scheme design and equipment technology， emphasizing the ideas of the observation layout design. According to different types of cloud systems and characteristics of precipitation variation, we have designed a tailored observational scheme, thus having obtained the continuous multiscale observation data of different types of cloud systems and precipitation. The series of scientific observation experiments provide data support for revealing the multiscale structural characteristics and the evolution way of the largerange cloud systems and precipitation in Sichuan and discussing the mechanisms of the occurrence, development and microphysical processes of cloud systems and precipitation.