The invention relates to a transmission mechanism for a fertilizer applicator, and aims to provide a fertilizer applicator transmission mechanism which is simple and compact in structure, low in cost and good in transmission effect. The fertilizer applicator transmission mechanism comprises an eccentric wheel (14) and a first pushing plate (15), and further comprises a second pushing plate (20) as well as a driving gear (21) and a driven gear (22) which are mutually meshed, wherein an upper rolling wheel (1501) and a lower rolling wheel (1502) are arranged on the first pushing plate; the lower rolling wheel is in fit with the eccentric wheel; the upper rolling wheel is positioned in an upper rolling wheel groove (16) which is fixedly formed in the outer side wall of a fertilizer box (1); an elliptic groove I is formed in the second pushing plate; a first rolling wheel (24) is arranged on the driven gear, and is positioned in the elliptic groove I; the fertilizer applicator transmission mechanism further comprises a circular disc (26) and a third pushing plate (27); an elliptic groove II is formed in the third pushing plate; a second rolling wheel (28) is arranged on the circular disc, and is positioned in the elliptic groove II.