The invention provides an optimum design method for a seaborne oil deposit new district economic optimality well pattern. The method comprises the steps that 1, single sad body reserve evaluation is performed; 2, development optimization combination of an available sand body is performed; 3, according to the reserve limit, a basic well patter is deployed; 4, single well economic benefit assessmentis performed, and economic and efficient oil well number and well location are optimized; 5, maximum injector producer distance optimization is performed, and the best well number and well location are optimized; 6, according to different wells, the oil production technology is optimized, and the single well production is improved; 7, the marine work platform scale, the platform type and the platform location are optimized. According to the optimum design method for the seaborne oil deposit new district economic optimality well pattern, the optimum design of the seaborne new district oil deposit, technology and maritime work integration economic optimality well pattern is achieved, and the practical and effective method is provided for economically and effectively employing the seaborne oil deposit new district.