A stone removing and soil preparation machine for farmland comprises a frame, a soil shoveling mechanism, a soil separating mechanism and a gravel conveying mechanism. A soil loosening mechanism comprises a plurality of soil loosening grids, a soil loosening grid supporting rod and suspension rods at two ends of the supporting rod. The soil separating mechanism comprises an openable-closable separating chain, two belt pulleys, a soil separating chain driving shaft and a soil separating chain driving wheel. The gravel conveying mechanism comprises a conveyor belt, a conveyor belt folding arm, a hydraulic cylinder, a driving sprocket wheel, a driven sprocket wheel, a driven shaft, a belt pulley and a conveyor belt wheel. The stone removing and soil preparation machine performs sand removing on the farmland and simultaneously performs soil preparation operations of stubble elimination, deep loosening, soil crushing, etc. Furthermore the quality of the farmland can be effectively improved.