An experiment with complete the full Platycodon grandiflorum seeds as the material,water control in sand culture method is adopted to improve the potted experiment,in the grains of sand(500 g/pot) are mixed with gradient process of super absorbent polymers (SAP),super absorbent polymers and Na bentonite (SAP+Na),super absorbent polymers and Ca bentonite (SAP+Ca),a total of three kinds of water conservation technique.This paper studied the effects of 3 water conservation techniques and different concentrations on the germination of seed and the seedling drought resistance of P.grandiflorum by planting in sands.The results showed that the 1g SAP,(1+9)-(1.5+2) g SAP+Na and(1+9) g SAP+Ca was beneficial to seed germination rate,root growth rate and increased leaf relative water content of P.grandiflorum,enhanced the activities of SOD and CAT,the contents of proline,soluble polysaccharide and soluble protein,effectively reduced the damage of heat stress on cell membrane.At the same time,the contents of chlorophyll and carotenoid,the efficiency of leaf photosynthesis were increased,the ASA and GSH contents were also increased,and thus effectively resisted the oxidative stress caused by drought stress.However,with the increasing concentration of spraying,P.grandiflorum decreased the ability to resist drought stress.In conclusion,mix a certain concentration of SAP,SAP+Na and SAP+Ca can effectively provide good environment for seed germination,alleviate the harm for P.grandiflorum seedling by drought stress.Mixed super absorbent polymers and Na(Ca) bentonite is more efficient than simply mixed super absorbent polymers.