The invention belongs to the field of seed processing and relates to a method for processing seeds by using a physical method, in particular to a method for injecting roegneria kamoji seeds by utilizing ion beams. The method comprises the following steps of: selecting dry roegneria kamoji seeds and controlling the water content to be 5-14 percent; putting the seeds on a plate of an ion beam injection device; and then, putting the plate in a target chamber to carry out low-energy nitrogen ion beam injection, wherein the injection dose of the low-energy nitrogen ion beams is 500-4,200 dose units, energy in the target chamber is 25 kilo electron volts, the flow magnitude of the nitrogen ion beams is 12 milliamperes, intermittent pulse injection is adopted, the pulse dose each time is 100-500, and the injection spacing interval each time is 20-30s, and the injection vacuum degree is 1.6*10<-2>-2.6*10<-2>. In the method, the germinating ability of the roegneria kamoji seeds is obviously improved, the seeds thrive in a seedling stage, and plants are strong; and the output of a single plant is increased, and the crude protein and the crude fat of the plants are both increased. The method can obviously improve the output and the quality of the roegneria kamoji and has higher application value.