Abstract: According to the DG/T 007-2019《Seed drill》, GB/T 9478—2005《Testing methods of sowing in lines 》and GB/T 27418-2017《Guide to the evaluation and expression of Uncertainty in Measurement》, the uncertainty of measurement results of the flow rate of seed drill was evaluated, the uncertainty evaluation formula of measurement results of flow rate of seed drill is derived, the factors affecting the measurement uncertainty of the flow rate of seed drill were analyzed, a method for evaluating the uncertainty of the flow rate of seed drill was put forward.