The invention discloses a portable liquid nitrogen transport tank comprising a liquid nitrogen tank body and a tank body bush. The tank body bush sleeves the outer wall surface of the top of the liquid nitrogen tank body; and the top of the tank body bush covers an opening formed in the top of the liquid nitrogen tank body. The portable liquid nitrogen transport tank also includes a sample rack, a refrigeration module, and a top cover. The sample rack is used for placing a sample and is arranged inside the liquid nitrogen tank body. The refrigeration module is arranged inside the liquid nitrogen tank body. The top cover detachably connected to the tank body bush is arranged right above the liquid nitrogen tank body; the bottom of the top cover is detachably connected to the refrigeration module; a nitrogen inlet for liquid nitrogen adding is formed in the top cover and is arranged right above the refrigeration module; the bottom of the nitrogen inlet is communicated with the inside of the refrigeration module; and the top end of the nitrogen inlet is connected with a sealed cover in a sealing manner. Therefore, the sample inside the liquid nitrogen tank body can be cooled effectively, so that the sample can be protected well.