Abstract: The study shows that power of per unit area in farmland work will reach 8.97 kW/hm² if general agricultural mechanization would come true. It is 49.5% above upper limit of reasonable power(2.25～6 kW/hm²) by comparing power equipped per unit area in some foreign countries and representative farm regions in China. Estimated by current consumption level, the consumption of diesel oil will reach 64.55 million tons when agricultural mechanization level strategically reaches 70% in 2020. Aiming at the target level of agricultural mechanization, a Logistic model of diesel oil demand is developed using statistical data in this paper. The results of verifying shows that the model fits well. On the basis of the forecasting results, and through the measures of innovating traditional farming system, adopting energy-saving machines and so on, the diesel oil consumption of agricultural mechanization may decrease to 50 million tons by bringing strategic measures into effect in 2020.