The invention relates to a novel tetrahydrofurfuryl ether compound modified titanium system heterogeneous catalyst composition. The synthesis method of the catalyst composition is simple and easy to control. According to the invention, the amount of the tetrahydrofurfuryl ether compound in the catalyst composition disclosed by the invention is lower as compared with the traditional symmetrical ether, and the activity of the modified catalyst is higher as compared with the traditional symmetrical ether; and simultaneously, the catalyst composition disclosed by the invention can be used for synthesizing polyisoprene rubber with excellent physical and mechanical properties, wherein the cis-1,4-structure content of the synthesized polyisoprene rubber is higher and more than 99%, the Mooney viscosity ML(1+4) at 100 DEG C of the rubber is adjustable in a range from 60 to 90, the tensile strength of the rubber is more than 35MPa, and 300% stretching stress of the rubber is more than 14MPa. The synthesized polymer can partially replace natural rubber to be used for tyre products.