Abstract: The paper aims to find the appropriate amount of phosphate fertilizer in rapeseed production and improve the efficiency. Taking the local variety ''Ningza 21'' as the test material, seed yield, economic benefit, utilization rate of phosphate fertilizer and soil nutrient content of rapeseed were studied by using different phosphate fertilizer dosages. The results showed that the growth and development of rapeseed could be promoted by adding phosphate fertilizer, and the plant height, stem diameter, number of branches, number of kernels per plan, number of seeds per silique and the weight of 1000 kernels all increased significantly by adding phosphate fertilizer, and when phosphorus application was 78.75 kg/hm2, the rapeseed yield was the highest and increased by 30% . The apparent utilization rate, physiological utilization rate and agronomic utilization rate of phosphate fertilizer of rapeseed increased first and then decreased. The apparent utilization rate of phosphate fertilizer varied from 9.35% to 15.88%, the physiological utilization rate varied from 40.82 to 71.21 kg/kg, and the agricultural utilization rate varied from 6.61 to 8.73 kg/kg. The partial productivity decreased with the increase of phosphate fertilizer dosage. The contents of some soil nutrients were increased by adding phosphate fertilizer, and the content of available phosphate in soil was obviously increased. The net profit of rapeseed increased with the increase of phosphorus application, while the net profit of excessive phosphorus application decreased. Based on the study, it is recommended that the applicable amount of phosphate fertilizer in rapeseed production in this region is 78.75 kg/hm2.