Heavy metal (HM) contamination of soil has posed an international risk to food safety. Biochar (BC) and humic acid (HA) are commonly employed to mitigate HM pollution. Both BC and HA can potentially influence the availability of cadmium (Cd) in soil. However, further investigation is required to understand their impacts and the mechanisms affecting Cd bioavailability and soil quality, particularly in the arid and semi-arid regions of northwestern China. Rice husk biochar (RBC) and HA were used on the actual polluted cropland soil in this investigation to reduce Cd pollution, improve soil quality, and promote maize plant growth. Results revealed that RBC, HA, and their combined application had significant effects on regulating the soil nutrient levels and Cd mobility and uptake by maize plants. The soil CEC and SOM levels rose the most in the T4 treatment (with 0.5 % RBC and 0.5 % HA added), by 13.10 % and 45.31 %, respectively, compared to the control. It was the T1 treatment (with 0.5 % RBC added) that reduced soil DTPA-Cd by 19.01 %, which was the most significant amount. Grain and root Cd levels decreased from 23.84 % to 44.27 % and from 25.03 % to 35.35 %, respectively. Average maize yields increased from 26.31 % to 51.74 %. Furthermore, the results of X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy indicated that the oxygen-containing functional groups (such as -OH and -COOH) present in RBC and RBC-HA could be considered as the primary mechanism of Cd adsorption. This research showed that RBC and HA can improve the quality of heavy metal-contaminated farmland, stop plants from taking in Cd, and raise maize yields.