When performing rice breeding, improved seed breeding, cultivation, and soil fertility tests in an agricultural community, quantitative seedling interpolation should be completed within the prescribed cell unit, and the required count value cannot be any error. When the rice transplanter is working, it is necessary to count the amount of transplanting. The transmission ratio of the drive shaft and the interpolation shaft can be used to obtain the number of inserted rows. At present, most of the transplanter insertion shafts cannot be installed on the shaft end of the counting device due to structural problems, and the counting device is difficult to fix. And the problem of missing meters due to inaccurate constraints has not been resolved. A design of a nonshaftend mounted counting device was presented based on the principle of precise constraint for the use of a rice transplanter. The sensor and the singletooth turntable were fixed on the clutch and the drive shaft respectively, and the counting device realized precise constraint on the rice transplanter, and compared the preset value of the counter with the actual number of inserted rows, it was verified that the counting device did not cause a leak. The test showed that the counting device can effectively achieve precise constraints in the narrow space on the mainstream rice transplanter models such as Jingguan and Kubota. The actual value was the same as the preset value, which proved that the counting device did not cause leakage when working.