Abstract: Taking ‘Huayouza 62’ as the test crop and rice hull biochar as the test conditioner material, eight treatments with four different rape planting densities combined with two biochar application levels were designed, namely T1（0%C+450 000）,T2（1%C+450 000）,T3（0%C+900 000）,T4（1%C+900 000）,T5（0%C+1 350 000）,T6（1%C+1 350 000）,T7（0%C+1 800 000）,T8（1%C+1 800 000）.The effects of biochar application combined with rape planting at different densities on rape growth and soil properties were studied, in order to provide reference for the efficient turning over of green manure rape and soil fertility in the new greenhouse.The results showed that the dry matter mass of T3 treatment without biochar and T4 treatment with biochar was the largest, which were 2 696.98 kg·hm^-2 and 3 474.37 kg·hm^-2 respectively.Soil physical properties, the R_0.25 value of T8 treatment was the largest, and other physical indicators changed little; among the chemical properties, the maximum nitrate nitrogen and available phosphorus in T5 treatment without biochar were 279.67 mg·kg^-1 and 52.33 mg·kg^-1 respectively, and the soil pH in T5 treatment was the lowest.After biochar application, the maximum soil organic matter, nitrate nitrogen and cation exchange capacity of T4 treatment were 19.64 g·kg^-1,227.30 mg·kg^-1 and 18.92 cmol（+）·kg^-1 respectively, which were significantly higher than the basic sample by 139.80%,506.78% and 35.63%.In biological characters, when there was no biochar application, the soil urease activity in T5 treatment was the largest, and the urease activity after biochar application was the largest in T4 treatment, which was 0.748 mg·g^-1·（24h）^-1,which was significantly increased by 25.29% compared with the basic value.Therefore, T4 treatment(1% biochar combined with 900 000 rape plants·hm^-2 density planting) improved the growth and soil properties of rape best, followed by T5 treatment(0% biochar combined with 1.35 million rape plants·hm^-2 density planting).