The invention provides a preparation method for 9,9-bis[6-(2-hydroxyethoxy)naphthyl]fluorene with high purity and high bulk density. The 9,9-bis[6-(2-hydroxyethoxy)naphthyl]fluorene with high purity and high bulk density is prepared by condensation of 9,9-bis(2-hydroxylnaphthyl)fluorene and ethylene carbonate under an alkaline condition with polar non-protonic solvents like N,N-dimethylacetamide,N,N-dimethylformamide, N-methylpyrrolidone, dimethylsulfoxide, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, triethylene glycol dimethyl ether, triethylene glycol diethyl ether and polyethylene glycol dimethyl (or diethyl) ether as reaction accelerators. The 9,9-bis[6-(2-hydroxyethoxy)naphthyl]fluorene has a purity (HPLC) of larger than 99.0%, a bulk density of larger than 0.4g/cubic centimeter, a loss on drying of less than 0.5% (at 120 DEG C, 30 min), and a melt absorption peak at 213 to 222 DEG C. The 9,9-bis[6-(2-hydroxyethoxy)naphthyl]fluorene has a powder X-ray diffraction peak (XRPD) spectrum which has a morphology as shown in a figure 3 of the invention and has characteristic diffraction peaks with 2theta values of 7.7 +/- 0.20, 8.8 +/- 0.20, 12.5 +/- 0.20, 14.3 +/- 0.20, 15.5 +/- 0.20, 17.7 +/- 0.20, 18.7 +/- 0.20, 19.5 +/- 0.20, 20.4 +/- 0.20, 20.9 +/- 0.20, 21.2 +/- 0.20, 22.2 +/- 0.20, 22.7 +/- 0.20, 23.1 +/- 0.20, 24.8 +/- 0.20, 25.4 +/- 0.20, 25.9 +/- 0.20 and 26.7 +/- 0.20.