Abstract: The development of offshore liquefied natural gas (LNG) production puts forward higher demand for heat exchanger, since it is the key component in LNG floating storage and regasification unit (FSRU). As a compact microchannel heat exchanger, printed circuit heat exchanger (PCHE) has a wide application prospect in LNG-FSRU because of its characteristics of small volume and high heat transfer efficiency. Considering the phase change phenomenon and the supercritical fluid in LNG vaporizer, a segmented thermal design method for PCHE is presented based on (LMTD) method. The temperature and the area of every segment could be calculated with boundary conditions and heat transfer correlations, and then the total heat transfer area of the vaporizer could be obtained. This method is proven to be reliable with 7.9% margin by contrasting the numerical result with the experimental one.