Abstract: This paper presents that the rural economy in the township level is a unit of rural economical developmemt and the expansion of rural production force is one of the key factors in the development of rural economy. On the base of comprehensive explanation on rural production force, the functions of agricultural engineering on expanding rural production forces have been analysed in term of the quality, quantity and structure of production force factors. Furtherly, with reference to the practical demands to the agricultural engineering from different aspects of rural production, the deep analysis has been given on the relationship between rural development and agricultural engineering.