The utility model relates to a gear reduction unit for peristaltic solid phase reactor, gear reduction unit includes the input shaft that is connected with the drive shaft of motor, input gear with the input shaft coaxial coupling, with input gear engaged with one -level gear, with one -level gear engaged with second grade gear, with the tertiary gear of second grade gear engaged with, with tertiary gear engaged with level four gear, output shaft with level four gear coaxial coupling, the output shaft is connected with transmission shaft / outer barrel, the one -level gear, the second grade gear, tertiary gear, level four gear teeth number increases in proper order. The utility model discloses a gear reduction unit for peristaltic solid phase reactor, for peristaltic solid phase reactor's rotation speed reducer, it is slow -speed of revolution energy with power input's high rotational speed conversion of energy to adopt the level four gear reduction to increase output torque satisfies peristaltic solid phase reactor's job requirement.