The invention relates to an engine clutch intermediate decelerating device of an agricultural caterpillar tractor. The engine clutch intermediate decelerating device comprises a flywheel end input flange, an input shaft driving gear, a bearing, a splined shaft, an input shaft driven gear, an output shaft driving gear, a bearing, an output shaft driven gear, a bearing set, a bolt and a gearbox body, wherein a main clutch comprises a clutch casing, a clutch driving plate, a clutch cover, a clutch hood and a clutch component; through power transmitted by the input flange, a high speed engine flywheel drives the input shaft driving gear to rotate; the input shaft driving gear drives the input shaft driven gear, the splined shaft and the output shaft driving gear to rotate; the output shaft driving gear drives the output shaft driven gear to rotate; and the output shaft driven gear drives the clutch driving plate to rotate. The process is decelerated in two stages through two pairs of gears, including the input shaft driving gear, the input shaft driven gear, the output shaft driving gear and the output shaft driven gear, so that high rotation speed can be reduced to a matched input rotation speed satisfying the traditional agricultural caterpillar tractor transmission system.