The invention provides a micro reduction box for a rice seedling transplanting machine. The micro reduction box comprises a reduction box body, an input shaft which is arranged in the reduction box body, a driven gear shaft, a driving gear shaft and an output shaft. An input gear is sheathed on the input shaft. A first driven gear and a second driven gear are sheathed on the driven gear shaft. A first driving gear and a second driving gear are sheathed on the driving gear shaft. One part of the second driving gear is provided with teeth and the other part of the second driving gear is not provided with teeth. An output gear is sheathed on the output shaft. The output gear is a combination of a toothed gear and an eccentric gear. An arc-shaped neutral-gear groove is arranged on the eccentric gear. The input gear is connected with the first driven gear through a chain. The second driven gear is engaged with the first driving gear. The second driving gear is engaged with the output gear. The micro reduction box for the rice seedling transplanting machine has the beneficial effect that the effect of multi-port output can be realized, the assembly is simple, the noise is low and the operation is convenient to perform.