Aimed to the problems revealed in latest grassland tests of the 9ST—460 vibration spacing scarifier, optimizations were carried out on the transmission mode of the parts, vibrating and loosening components. The results of comparing test indicated that the improved device ran steadily and showed good performance. The bulk density of soil decreased but water content increased after scarifying. The yearly average economic benefit increased by 155RMB/hm2 in next 3 years after scarifying, which well fulfilled the requirements of grassland improvement procedure.