A series of UV curable polyurethanes that were compounded based on polydiethylene glycol 2000 as soft segments,different glycol chain extenders and isophorone diisocyanate (IPDI) as hard segments,and 2 Hydroxyethyl acrylate (HEA) as blocking agent were synthesized by prepolymer method. The relative activities of different glycol chain extenders as chain extenders were analyzed: the structure of UV curable polyurethane was characterized by infrared spectral,and the influences of different glycol chain extenders on the mechanical performance,heat resistance performance and usability of cured film were studied. The results show that under 80 ℃,the reaction speed of ethylene glycol and phenyl isocyanate(PI) is the fastest,the speed of 1,2 propylene diatomic alcohol and PI is the slowest,and 1,4 cyclohexane dimethanol(CHDM) as chain extender of PU has the best mechanical properties and heat resistance.