The invention discloses a sensor and method for measuring a gravitational potential three-order differential quotient based on an atom interference effect, and relates to the technical field of cold atoms in atomic and molecular physical subjects. The sensor is composed of two cold atom interference devices, the central axes of two interference regions are overlapped, two vacuum containers are communicated into a whole in the direction of the central axes, and meanwhile a two-dimensional magneto-optical trap region is arranged. The measuring method is characterized in that the collecting process of a single set of original data points comprises the following steps that the two devices are used for emitting four synchronous faller cold atom groups, an initial state is prepared, synchronous correlation operations based on common Raman laser beams are carried out, and a final state is detected; the data processing process comprises the steps of converting n sets of original data points into n two-order phase difference data points and carrying out fitting processing. According to the system and the method, the influence of external interference and internal noise on measurement can be greatly restrained, and important significance is achieved for resource exploration, geologic structure analysis, physical geography study and other fields.