Abstract: Taking Codonopsis pilosula as experimental material, and adopting the method of two factor random block, the effects of mulching time and amount on soil water and heat status and the yield of Codonopsis pilosula were studied, in order to provide reference for the cultivation technology and popularization of Codonopsis pilosula under straw mulching.The results showed that straw mulching significantly increased the soil water content of the 0-20 cm soil layer in the late growth stage of Codonopsis pilosula,that the average soil water content of A2 B3 was 11.39%,which was higher 3.55% and 5.86% than without covering in open field and plastic film outcrop planting, respectively.The soil temperature of Codonopsis pilosula mulch covered with straw showed that it was cooled in the early stage and kept warm in the later stage, and the cooling rate was 1.08 ℃ lower than without covering in open field, and 1.04 ℃ lower than plastic film outcropping.At the same time, this study showed that the time of straw mulching of Codonopsis pilosula should be sooner rather than later.The average yield of finished medicine of Codonopsis pilosula with transplanting coverage was 8 881.33 kg·hm^-2,which was 10.38% higher than that of seedling coverage.When the amount of straw mulching was 10 500-13 500 kg·hm^-2,the yield of Codonopsis pilosula was the highest, which was 9 718.48 kg·hm^-2,and the yield was increased by 27.21% and 25.32% compared with no covering in open field and plastic film outcrop planting, respectively.Straw mulching had a significant cooling effect on Codonopsis pilosula,protecting moisture content and increasing production, which provides support for popularization and application of the straw mulching cultivation technology in Codonopsis pilosulaplanting.