Due to its low viscosity and weak sand carrying capacity，the slickwater fracturing fluid is often unable to meet the efficient filling of proppant in complex fracture networks post-fracture. Based on the theory of bubble suspended sand，a CO₂ suspension proppant technology was proposed and the CO₂ suspension sand effect in slickwater fracturing fluid was evaluated under normal temperature and pressure，high temperature and high pressure，respectively. The results showed that the surface modified coating of suspended proppant could play a stable gas-solid bridging effect. For the surface modified suspended proppant，the adsorption of CO₂ and the bridging effect of proppant could effectively reduce the specific gravity of proppant，significantly slow down the settling speed of the proppant in slickwater with a reduction of 99%，being of 0.15 cm/min，thus achieving the effect of “low formation damage and high sand carrying capacity”. The performance of CO₂ suspended sand under the condition of normal temperature and pressure was mainly affected by the viscosity of slickwater. The degree of suspension and stable suspension duration increased with the increase of viscosity of slippery water fracturing fluid，but it is basically not affected by sand concentration. Under the condition of high temperature and pressure，carbon dioxide was in a supercritical state（SC-CO₂），but it could still adsorb on the surface of suspended quartz sand and play a certain suspension role，causing a large amount of suspended quartz sand to be suspended during the stirring process. CO₂ suspension proppant technology can significantly improve the sand carrying capacity of slickwater，and has important practical significance to reduce the risk of sand plugging in complex fracture networks and improve the efficiency of oil and gas well reconstruction by efficient proppant filling.