To improve the dissolution and bioavailability of poorly soluble drugs, novel nanosuspensions using co-processed nanocrystalline cellulose-sodium carboxymethyl starch (NCCS) as a synergetic stabilizer were first designed.Co-processed NCCS was prepared by means of homogenization. Poorly soluble baicalin (BCA) was used as a model drug. BCA nanosuspension (BCA-NS/NCCS) using co-processed NCCS as a dispersant was prepared via homogenization and further converted into the dried BCA nanosuspension particle (BCA-NP/NCCS) via spray drying. The influence of NCCS on the dispersion efficiency of BCA-NS/NCCS was investigated. Morphology and crystal characteristic of NCCS and BCA-NP were analyzed. The dissolution and bioavailability evaluation were performed to investigate the feasibility of NCCS as a stabilizer for BCA-NS/NCCS and BCA-NP.The optimum 50% concentration of NCCS (nanocrystalline cellulose [NCC]:sodium carboxymethyl starch [SCS]=60:40) could be mostly beneficial for formation and stability of BCA-NS/NCCS. NCCS could completely prevent aggregation of BCA-NP during spray drying and enhance the redispersibility as well as dissolution of spray-dried BCA-NP, which might be attributed to "brick-concrete"-based barrier effect of NCCS and the swelling capacity of superdisintegrant SCS. The crystal state of NCC and BCA presented in BCA-NP/NCCS remained unchanged during the homogenization. The BCA-NP/NCCS exhibited a fast dissolution rate and significantly enhanced bioavailability of BCA. The AUC of the BCA-NP/NCCS (8,773.38±718.18 µg/L·h) was 2.01 times (<0.05) as high as that of the crude BCA (4,354.61±451.28 µg/L·h).This study demonstrated that novel surfactant-free nanosuspensions could be prepared using co-processed NCCS as a synergetic stabilizer and also provided a feasible strategy to improve the dissolution and oral bioavailability of poorly soluble drug.