The effects of four passivators, including sepiolite, lime, iron-modified woody peat and weakly alkaline bio-organic fertilizer, on in situ remediation of cadmium （Cd）-contaminated paddy soil and soil enzyme activities were studied. The results showed that the four passivators could improve soil pH and rice yield, reduce Cd bioavailability in soil and Cd content in brown rice, and the Cd content in brown rice was lower than the national food safety standard limit （Cd≤0.2 mg/kg）. The treatment of applying 1 500 kg/hm² weakly alkaline bio-organic fertilizer had the best effect on increasing soil pH, from 6.07 to 7.00, an increase of 13.2%. The treatment with 2 500 kg/hm² iron-modified woody peat had the largest decrease in soil available Cd and brown rice Cd content, from 0.538 mg/kg to 0.232 mg/kg and 0.260 mg/kg to 0.076 mg/kg, respectively, with a decrease of 56.8% and 70.8%. The treatment of 1 500 kg/hm² weak alkaline bio-organic fertilizer had the best effect of increasing rice yield, with an increase of 6.4%. The activities of invertase, urease and catalase in soil were increased to varying degrees after the application of the four passivators. Among them, the treatment of applying 1 200 kg/hm² of quicklime had the best effect on improving the activity of invertase in soil, the treatment of applying 2 500 kg/hm² of iron-modified woody peat had the most obvious effect of improving the activity of urease in soil, the treatment of 1 500 kg/hm² weak alkaline bio-organic fertilizer had the best effect on improving the activity of catalase in soil. Correlation analysis showed that the Cd content in brown rice was negatively correlated with the activities of soil invertase, urease and catalase, indicating that the application of these four passivators could reduce the Cd content in brown rice. Based on the effects of four passivators on soil available Cd, Cd content in brown rice and soil enzyme activity, iron-modified woody peat is more suitable for remediation of cadmium-contaminated soil.