The invention relates to a ground process treatment system and a ground process treatment method for different treatment scales of a multi-set station yard. An oil coming manifold of each set is connected with a ball reception barrel, a heating furnace and an oil-gas-water three-phase separator in sequence; oil outlets of all the oil-gas-water three-phase separators are connected with an overflowing and settling tank, a purified oil storage tank and an oil delivery pump in sequence and then are connected with a crude oil external delivery pipeline; the oil coming manifold, the ball reception barrel, the heating furnace and the oil-gas-water three-phase separator of each set are also communicated with other sets through manifolds; all connection manifolds are provided with valves. According to the ground process treatment system and the ground process treatment method, through the series-parallel connection of different devices of different horizons and the series-parallel connection of the different devices of the same horizon, the problem about the proportional distribution of a crude oil treatment scale on the premise that a double-set development scale is not determined is solved; a ground process for a multi-set gathering and transportation station yard of an oilfield is optimized; the energy consumption is decreased; the ground construction investment is saved; the comprehensive utilization benefit of the oilfield development is improved.