The invention relates to cordyceps sinensis nano powder, cordyceps sinensis freeze-dried nano powder tablet and a preparation method of the cordyceps sinensis freeze-dried nano powder tablet, belonging to the field of medicaments and health care products. The cordyceps sinensis freeze-dried nano powder tablet is obtained by carrying out freeze-drying on the cordyceps sinensis nano powder only containing cordyceps sinensis total component or is obtained by smashing a freeze-dried product into coarse powder and then pressing the coarse powder into tablets, wherein particle size of the cordyceps sinensis nano powder is 10-800nm. Under protection of a jacket cooling device, a high-energy nano ball mill is adopted for smashing cordyceps sinensis into nanoscale micro powder, the particle size of the smashed cordyceps sinensis is 10-800nm, the smashed cordyceps sinensis nano powder is added into appropriate amount of purified water to be made into cordyceps sinensis nano powder homogeneous size, vacuum freeze-drying is directly carried out to obtain freeze-dried tablets, or freeze-dried products with different moisture contents are made, then the cordyceps sinensis nano powder is added and is pressed into tablets, and packaging is carried out to obtain the cordyceps sinensis freeze-dried nano powder tablet. The cordyceps sinensis freeze-dried nano powder tablet disclosed by the invention has no tonic loss or damage, good taste and uniform and stable product quality, can be rapidly disintegrated, has high human bioavailability and is convenient to carry and use.