Agricultural and food processing wastes, such as corn steep liquor (CSL) and myo-inositol (MI), are promising biostimulants for enhancing crop resilience under abiotic stress. While our previous work established the effectiveness of CSL-MI co-application in mitigating salt stress in Brassica rapa, critical knowledge gaps persist regarding their combined mechanisms in regulating root system architecture and nutrient acquisition efficiency. Here, we investigate the comparative efficiency of CSL and MI in promoting growth and nutrient acquisition in Chinese cabbage under saline conditions (2.25g·kg⁻¹ NaCl stress). Plant biomass, root architecture, photosynthetic pigment content, and total nitrogen and total phosphorus concentrations were measured. We found that co-application of CSL and MI increased the shoot fresh weight by 124.48% and the root fresh weight by 169.49% and plant total nitrogen content increased by 39.49% and plant total phosphorus content increased by 56.87% as compared to the salt treatment alone. The results emphasize the potential of agricultural waste-derived biostimulants for sustainable crop production under salt stress, with Chinese cabbage exhibiting similar responsiveness to combined CSL-MI application compared to other cabbage under similar stress.