The invention relates to an oil-gas separation mixed transportation pressurization skid and a process thereof. The oil-gas separation mixed transportation pressurization skid includes a filter, a heating furnace, a buffer separation tank, a gas-liquid separator, a first oil transfer pump, a second oil transfer pump, a compressor and valves, and the filter, the heating furnace, the buffer separation tank, the gas-liquid separator, the first oil transfer pump, the second oil transfer pump, the compressor and the valves are arranged on a skid seat. The process includes the steps that incoming oilis filtered through the filter into the heating furnace and then enters the buffer separation tank; associated gas is separated from crude oil by the buffer separation tank, and the separated crude oil is pressurized by the oil transfer pumps for outward transportation; and the separated associated gas is separated by the gas-liquid separator for secondary filtration, and then pressurized by thecompressor and transported outwards with the crude oil at the same time. According to the oil-gas separation mixed transportation pressurization skid and the process thereof, pure liquid phase delivered by pumps is ensured, the problems of high failure rate and short service life of the pumps caused by oil-gas mixing transportation are solved, vibration, heating and other adverse effects caused bydirect mixed transportation of the oil and gas through the pumps can be eliminated, the service life of the pumps is prolonged, the maintenance cost is reduced, the separated associated gas is transported outwards by the compressor, the associated gas in the crude oil is fully recycled, the resource utilization rate is improved, the environment is protected, and the process can effectively improve the efficiency of equipment operation.