The wear behavior of different plant abrasive to 45# steel was studied by using an abrasive rubber wheel tester. The worn surface of the frictional samples morphology was observed by using Scanning Electron Microscopy, and the wearing mechanism of different abrasive to 45# steel was analyzed. The results show that: on the experiment conditions, the wear loss from big to small is alfalfa abrasive, corn abrasive and wheat abrasive, and the wear rules of corn abrasive and wheat abrasive are similar, but the wear loss of alfalfa abrasive is much higher than the former two. The wear dominant mechanism of the wheat abrasive to 45# steel is mechanical polishing, the wear dominant mechanism of the corn abrasive to 45# steel is mechanical polishing and adhesive wear, the wear dominant mechanism of the alfalfa abrasive to 45#steel is micro-cutting and adhesive wear.