Abstract: In order to select and optimize the varieties of soil conditioner, by taking the treatment with no conditioner as the control group (CK), the experiment was carried out on the effect of three kinds of soil conditioner (treatment 1 with Yuetianwanshan, treatment 2 with Mugaisuanqing, and treatment 3 with Greenhouse) on the pH value of soil in cultivated land and the yield and quality of cauliflower. The results showed that: on the basis of conventional fertilization, the average pH value of soil under the treatments with the three soil conditioners was respectively 5.8, 5.6 and 5.7, which respectively increased by 18.4%, 14.3% and 16.3% compared with the control group. The three treatments with soil conditioner had an improvement effect on the agronomic characters of cauliflowers. The leaf length & width, bulb diameter, single head weight and commercial properties were all increased to different degrees compared with the control group. Furthermore, the incidence rate of clubroot disease of cauliflowers (3.3%) was significantly lower than that of CK (23.3%). The yields of treatment 1 and treatment 3 were respectively 1 834.4 kg and 1 884.4 kg per 667 m², which increased by 2.8% and 5.6% compared with CK, but the yield-increasing effect was not significant. The results showed that different soil conditioners could improve the pH value of soil, the agronomic characters of cauliflowers and the resistance to clubroot disease of cauliflowers, meanwhile, there was also a certain promoting effect of soil conditioner on the yield of cauliflowers.