NOVELTY - Usage method of partial hydrogenation 5C fraction involves adding partial hydrogenation fraction into rectifying tower (A), obtaining crude isoamylene fraction, mixing with methanol, performing catalytic etherification reaction, converting crude isopentene to methyl tert-amyl ether to obtain etherification reaction solution, performing distillation of etherification reaction solution in rectifying tower (B), obtaining eicosapentaenoic ether, washing, carrying out catalytic hydrogenation, rectifying obtained solution, and obtaining 4C fraction, pentane and cyclopentene.    USE - Usage method of partial hydrogenation fraction for producing tert-amyl methyl ether, cyclopentadiene, cyclopentane and pentane. The byproduct is used as fuel.    ADVANTAGE - The high-purity tert-amyl methyl ether, cyclopentadiene, cyclopentane and pentane are produced using partial hydrogenation 5C fraction.    DETAILED DESCRIPTION - Usage method of partial hydrogenation 5C fraction involves adding partial hydrogenation fraction into rectifying tower (A), obtaining crude isoamylene fraction from tower top and cyclopentene fraction from bottom of tower, mixing the crude isoamylene with methanol, performing catalytic etherification reaction using etherification catalyst, converting crude isopentene of 2-methyl-1-butene and 2-methyl-2-butene to methyl tert-amyl ether to obtain etherification reaction solution, performing distillation of etherification reaction solution in rectifying tower (B), obtaining eicosapentaenoic ether from top of tower and methyl tert-amyl ether from side line of tower, washing eicosapentaenoic ether, removing methanol, carrying out catalytic hydrogenation using catalytic hydrogenation catalyst to obtain hydrogenation reaction solution, rectifying hydrogenation reaction solution in rectifying tower (C), obtaining 4C fraction from top of tower, distilling material in tower (C) in rectifying tower (D), obtaining pentane from top of tower, rectifying material in tower (D) in rectifying tower (E), obtaining cyclopentene from top of tower and material containing cyclopentane and heavy component fraction from bottom of tower top, subjecting material in tower (E) to catalytic hydrogenation, processing monoolefin to alkane to obtain hydrogenation reaction solution, rectifying hydrogenation reaction solution in rectifying tower (F), obtaining cyclopentane from top of tower and using tower material as fuel for heavy constituent.