The invention relates to an optimized design method of nested observing systems in geophysical exploration and collection. The method comprises the steps that the receiving line distance for the primary collection is 2 times of the surface element lateral dimension, the exciting line distance is 2 times of the surface element longitudinal dimension, the receiving line distance for the secondary collection is unchanged, the exciting line distance is unchanged, a receiving line is parallelly shifted by 2 times of the surface element lateral dimension, and an exciting line is parallelly shifted by 2 times of the surface element longitudinal dimension till the collection line distance is equal to 2<2> times of the surface element dimension, so that a series of observing systems is obtained. The optimized design method has the advantages that high-density data collection can be realized on the basis of effective cost control, new and old data can be sufficiently utilized, the attributes of the observing systems are uniform and symmetrical, and the final imaging effect is optimum.